(CNN) -- United Nations observers finally entered the northwestern Syrian town of al Haffa Thursday to find it deserted after days of intense fighting.
Most government institutions, including the post office, had been set afire from the inside, said Sausan Ghosheh, spokeswoman for the U.N. mission in Syria.
Archives were burned, stores were looted and set ablaze, and homes appeared to have been ransacked.
The ruling Baath Party Headquarters in al Haffa had been shelled and appeared to have been the site of heavy fighting, Ghosheh said. Parts of heavy weapons lay scattered about the town. Cars, both civilian and security, had been set afire.
And in the air was the stench of decaying bodies, now sadly familiar to Syrians. The number of casualties was not clear. Fighting appeared to be ongoing in pockets, Ghosheh said.
Government forces fought the rebels in al Haffa and said they had reclaimed the town in Latakia province. The rebels, in turn, admitted to a forced retreat.
The London-based Syrian Observatory for Human Rights said al Haffa had been shelled for eight consecutive days.
U.N. observers had attempted to reach the town Monday but were blocked by angry supporters of the government. Now, after seeing the destruction, Ghosheh said, the United Nations reiterated its plea for all parties to put down their guns.
Violence has surged in Syria in recent weeks as a peace plan brokered by U.N. and Arab League joint special envoy Kofi Annan has fallen apart amid violence by government and opposition forces.
In the Syrian capital, a suicide bomber blew up an explosives-laden car near a Shiite shrine Thursday, the state news agency said.
The bombing occurred at a Damascus parking lot near the shrine of Sayyidah Zaynab, which houses the tomb of the Prophet Mohammed's granddaughter, the official Syrian Arab News Agency said.
At least 14 people were wounded. It was not clear whether the shrine was the bomber's intended target.
State media showed photographs of a crater and mangled, charred cars in the parking lot. A YouTube video posted shortly after the explosion showed black smoke billowing from the vicinity of the shrine, which is near two Syrian government security buildings.
Gunfire could be heard, said the opposition Local Coordination Committees of Syria, which collects reports of casualties and violence.
Syria's official news agency reported that a member of al Qaeda, whom it identified as Mohammad Houssam al-Sadaqi, had been arrested. It said al-Sadaqi had been planning to blow himself up during Friday prayers inside al-Rifai mosque and had confessed that others were planning similar actions in other mosques in Damascus.
It also said that 22 members of the army, law enforcement personnel and civilians were buried Thursday.
CNN cannot independently confirm accounts of violence as access to Syria by journalists has been severely limited by the government.
While state-run media blamed "armed terrorists" for the attack in Damascus, the opposition accused government forces of conducting a campaign of raids and arrests against those participating in demonstrations in the capital.
The arrests in the ethically mixed Damascus neighborhood of Hajar al-Aswad followed a demonstration Wednesday night in the area, the LCC said.
It reported bombardment again Thursday of several Syrian cities, including Idlib, Aleppo and Homs.
In the Damascus suburb of Douma, the opposition group reported intense and incessant bombing. It said residents were imploring United Nations monitors to head their way.
At least 60 people were killed nationwide Thursday, the group said.
The escalating violence prompted the U.N. peacekeeping chief Herve Ladsous this week to call the Syrian conflict a civil war. The Syrian government, however, dismissed that claim.
"Any talk about civil war in Syria doesn't reflect the reality," the government said in a statement released through the state news agency.
"Syria is not witnessing a 'civil war' but rather a struggle to uproot the plague of terrorism."
President Bashar al-Assad has been under international pressure to end a crackdown that began in March 2011 with an attempt to crush an anti-government protest movement that has grown into an armed rebellion.
Al-Assad has denied opposition assertions that he is targeting civilians, and he has repeatedly described the crackdown as a fight against "armed terrorists" bent on destabilizing Syria.
France plans to propose that the United Nations be given the power to enforce Annan's peace plan, including considering the possibility of implementing a no-fly zone, to end the bloodshed.
"If you can't call it a civil war, then there are no words to describe it," said French Foreign Minister Laurent Fabius, who became the first Western government official to label it as such.
He called on Russia to reverse its opposition to international action led by the United Nations. Russia and China, trade allies of Syria, have blocked Security Council attempts to pass a resolution calling for an end to the violence and for al-Assad to step down.
Fabius is urging Russia to authorize the use of force in Syria under Chapter 7 of the Charter of the United Nations, which allows for action to stop the escalation of targeted violence.
"The time to make a decision has arrived," Fabius said.
Russia has repeatedly refused to support any action against Syria, accusing the West of using a Security Council resolution that called for the protection of civilians in Libya to support its successful effort last year to oust Moammar Gadhafi from power.
Meanwhile, a human rights group accused al-Assad's forces of killing civilians in organized attacks.
In a 70-page report, Amnesty International listed crimes against humanity and war crimes by Syrian forces as part of a government attempt to take revenge on towns and communities suspected of supporting rebels.
The rights group called on the U.N. Security Council to refer Syria to the International Criminal Court in the Hague to face charges.
U.N. advisers on the prevention of genocide issued a statement Thursday saying that the recent mass killings of civilians in Houla and Qubeir represent "an alarming escalation in targeted attacks against civilians," and urged that the Security Council consider the request of the High Commissioner for Human Rights to refer the situation to the International Criminal Court at the Hague.
"With the increasing violence and deepening sectarian tensions, the risk of further mass atrocity crimes is high," their statement said. "The time for action is now."
Opposition groups estimate more than 12,000 people have died in the uprising.
CNN's Saad Abedine, Moni Basu and Joseph Netto contributed to this report.