(CNN) -- Opposition groups called Monday for the international community to protect civilians in the besieged western city of Homs, which the Local Coordinating Committees of Syria said was the site of eight of the 12 killings it tallied on Monday.
"The Syrian National Council is calling on the Arab League and the U.N. to provide protection to the civilians in Homs as a disaster area," a senior Arab League official said. "They want U.N. troops on the ground, which would require approval from the U.N. Security Council and the cooperation of the Syrian government. It a complicated process yet the support of humanitarian agencies ... may be essential at this stage."
The council is a recently formed opposition group supported by a coalition of Egyptian activists and based in Turkey.
In addition, the Syrian Revolution General Commission, an umbrella opposition group that boasts among its members some of the most prominent activist groups from cities across Syria, released a statement calling on the United Nations and the Arab League to declare the city a disaster area.
Monday's total death toll of 12 included two girls and a woman, said the LCC, an opposition group that organizes and documents protests.
At least 16 people were killed Sunday in shelling and gunfire in Homs, a hotbed of anti-government sentiment and a government-led crackdown, according to the LCC.
Shelling of suburbs and arbitrary arrests were continuing, it said.
CNN could not confirm the reports. Tough media restrictions in Syria have made it hard to verify events on the ground.
The government said it agreed to pull its army off the streets, release people jailed since the protests began in March and allow international journalists and Arab League observers to monitor the moves, Arab League ministers announced Wednesday.
But opposition activists say that has not happened, and reports of violence in Syria have continued.
On Sunday, Syria's ambassador to the league, Youssef Ahmad, knocked its leaders' comments, according to the government-run Syrian Arab News Agency.
"The AL (Arab League) Secretariat is supposed to play its role in coordinating between the Syrian government and the ministerial committee, not proclaim itself a party against the Syrian government," the ambassador said, according to SANA.
The news agency also said that Syria's foreign minister, Walid al-Moallem, sent letters to his counterparts in various countries, accusing the United States of inciting violence.
In a bid to end the unrest, officials have called on Syrians to lay down their weapons -- a request that was discouraged by the United States -- al-Moallem wrote, SANA said.
Journalist Mohamed Fadel Fahmy contributed to this story