STORY HIGHLIGHTS
- NEW: Syrian forces open fire on anti-al-Assad protesters across border, state media reports
- Lebanese PM Mikati is staying in power, despite his offer to resign
- Mikati is backed by Hezbollah
- Blame over Lebanese intel chief's death is largely aimed at Syrian regime
(CNN) -- A day after the most high-profile assassination in Lebanon in more than seven years, accusations over who's responsible homed in on the Syrian regime of Bashar al-Assad.
Prime Minister Najib Mikati, a billionaire supported by Hezbollah, announced Saturday that he plans to stay in power, despite having offered his resignation to appease those who claimed al-Assad was behind Friday's car bombing that killed Lebanon's intelligence chief, Brig. Gen Wissam al-Hassan.
"To hold me personally responsible for the assassination is unfair," he told reporters. "I have always respected and admired al-Hassan, who has done great things for Lebanon."
Mikati's decision to stay heads off a power vacuum in Lebanon's government, as sectarian tensions flare particularly as the effects of Syria's 19-month civil war spill across borders and threaten the region.
Don't know who is who in Lebanon? A guide to key players

Smoke billows in Tripoli's Bab al-Tabanneh neighborhood during clashes between Alawites, an offshoot of Shiite Islam, and anti-government supporters on Monday, October 22. Fighting continued in Tripoli and Beirut, where a top police official was killed in a car bombing. At least two people were killed in Tripoli and several wounded in Beirut.
The coffin of intelligence chief Gen. Wissam al-Hassan arrives in downtown Beirut during his funeral procession on Sunday, October 21. Hassan, a prominent Lebanese figure opposed to Syrian President Bashar al-Assad, died when a powerful bomb exploded in an upmarket Beirut suburb on October 19, sparking calls for Prime Minister Najib Mikati and his government to quit.
An anti-government protester waves a pre-Baath Syrian flag at a demonstration outside the govermental palace in Beirut, Lebanon, after a funeral for al-Hassan and his bodyguard on Sunday. The two men and one other person were killed in a car bombing on Friday.
Demonstrators face off with Lebanese security forces on Sunday as they try to storm the palace.
Protesters climb a statue Sunday during the funeral of al-Hassan.
A demonstrator runs for cover from tear gas fired by Lebanese police on Sunday.
Anti-government protesters demonstrate outside the government palace on Sunday.
Protesters react to tear gas being fired at them by Lebanese police officers on Sunday.
Protesters hurled sticks, stones and flags on Sunday. A number of injuries were reported, Lebanon's National News Agency said.
Officers and mourners gather around al-Hassan's coffin during his funeral on Sunday.
The mother and wife of the slain intelligence officer mourn Sunday.
Lebanese officers of the Internal Security Forces carry the intelligence chief's coffin on Sunday.
Sunday's anti-government protests came after a series of political speeches given to the crowd gathered in Beirut's central square.
A Lebanese man holding the national flag watches the funeral procession on Sunday.
A woman with a cross and a rosary prays at a poster with an image of al-Hassan, during a protest Saturday, October 20, against his killing.
People set up tents and gather outside the headquarters of the Prime Minister of Lebanonon on Saturday night.
A damaged building is pictured in Beirut's predominantly Christian district of Ashrafiyeh on Saturday.
Smoke rises from burning tyres blocking the main northern entrance of Beirut on Saturday. Protesters blocked some roads in Beirut, Tripoli in the north, Sidon in the south, and the Bekaa Valley in the east.
Lebanese security forces inspect damage in Ashrafiyeh on Saturday.
A damaged building stands Saturday with windows knocked out and belongings from within strewn about.
A worker on Saturday sweeps shattered glass outside damaged shops.
Lebanese men block a road leading to the airport in Beirut to protest against the assassination of top intelligence official Wissam al-Hassan in a blast on Friday, October 19.
Lebanese light candles during a vigil near the site of the car bomb attack on Saturday.
Lebanese people take part in a candlelight vigil near the site of the car bomb blast.
A Lebanese firefighter douses cars at the site of an explosion in Beirut's Christian neighbourhood of Ashrafieh.
Lebanese firefighters douse burning vehicles.
A car burns after an explosion in Beirut's predominantly Christian district of Ashrafiyeh.
Lebanese Red Cross aid workers help a wounded man. Dozens were injured, some seriously, and others were slightly hurt, a senior hospital official said.
Lebanese security forces and rescue workers gather at the site of the explosion.
Lebanese men evacuate a wounded woman from the scene of the car bomb.
Lebanese police stand by a crater as they secure the site.
Civil defense members help a wounded man in the immediate aftermath.
A wounded woman is carried from the area. The attack did not target any political figure, the Lebanese National News Agency says.
A civil defense member helps a wounded man.
A wounded woman gets assistance.
A woman is helped by a Lebanese soldier after the explosion.
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
Lebanon on edge after officer's death
HIDE CAPTION
Photos: Lebanon on edge after officer's death
Syria under suspicion for Lebanon attack
Sunni community will 'unleash its wrath'
Beirut car bomb: Suspects at-large still
The senior Lebanese security official and at least nine others died in the explosion in the typically peaceful and cosmopolitan Ashrafiyeh district of East Beirut.
The attack -- in broad daylight, at one of the capital's busiest intersections -- left a crater more than a meter deep and was just the kind of thing al-Hassan had worked to prevent.
But beyond its potential impact on Lebanon's security, al-Hassan's life and death illustrates the deep political and religious fissures within Lebanese society, believed to be exacerbated by its neighbor's internal conflict, where at least another 123 people were killed Saturday amid fighting that has left tens of thousands dead.
Saad Hariri, a Lebanese opposition leader and former prime minister, told CNN that he had no doubt that the Syrian leader was responsible for Friday's deadly strike.
Hariri accused al-Assad of "killing his own people" and said "he will not think twice" about killing Lebanese in order to protect himself.
"The message from Damascus today is anywhere you are, if you are against the regime from Lebanon, we will come and get you. ... No matter what you try to do, we will keep on assassinating the Lebanese," said Hariri, who blames the 2005 assassination of his father, former Prime Minister Rafik Hariri, on the Assad government.
Lebanon on edge after attack
Syrian armed forces opened fire from across the border on anti-al-Assad and anti-Hezbollah protesters in northern Lebanon, the Lebanese state-run National News Agency reported. The protesters burned al-Assad's effigy and Hezbollah flags before being fired upon, NNA reported, citing its reporters at the scene.
Walid Jumblatt, a Druze politician and influential power broker in Lebanon's rough-and-tumble political landscape, also echoed Hariri's comments.
Jumblatt told CNN he blames Friday's murder on the Assad government and has expressed concerns over his own safety.
He said the Syrian-backed murderers of al-Hassan "can hit you any place anywhere."
"I don't feel safe," he added, talking to CNN in his hillside home outside the capital.
When asked if he thought al-Hassan's killers would be captured, Jumblatt replied: "Sometimes you have justice -- I mean procedural justice according to the rules, and sometimes you have natural justice when one day the killer will be killed. One day the killer will die. You just have to be patient and one day you will see your enemy floating in front of you in the river."
Under Assad, Syria has continued to influence the politics of its smaller neighbor despite withdrawing troops from Lebanon in 2005 following Rafik Hariri's assassination.
Last year, Damascus maneuvered to topple Hariri's son Saad as prime minister by persuading Jumblatt to abandon the majority coalition in parliament, which left Hezbollah to play kingmaker in protracted negotiations to form a new government.
Tensions have since boiled over in Lebanon following Friday's attack as enraged citizens blocked roads and clashes erupted in the port city of Tripoli between supporters and foes of Syria's government.
The Lebanese president declared Saturday a day of national mourning in decrying the "abominable crime" in a statement.
But the prime minister's failure to appear publicly after the explosion elicited criticism, including from one protester in Beirut who said, "This government is killing us by not doing anything. It is not acting like a government. It is like a ghost government."
The U.N. Security Council also weighed in Friday, calling for "the perpetrators, organizers, financiers and sponsors of this crime" to be brought to justice.
CNN's Nick Paton Walsh contributed to this report from Beirut