Even the death toll from the collapse Wednesday was disputed, The New York Times reported. The government said 16 people were killed; the dissidents, about 70.
A dissident in Hama using the name Abu Zafer told the Times via Skype he knew of at least 54 people whose deaths had been confirmed. He said 15 other bodies not yet identified were at the morgue.
Many of the buildings involved were constructed of cinder blocks with nothing holding them together, he said.
"The houses there are so fragile, built without real foundations, so a bullet could practically destroy a house," he said.
The Syrian National Council, an opposition group, issued a statement from Istanbul, saying the government of President Bashar Assad had violated the U.N. cease-fire. On the other side, the official Syrian Arab News Agency, said a bomb went off while a terrorist group was moving into one of the houses.
The Arab League was to hold an emergency meeting Thursday in Cairo to discuss Syria.
Assad's government, meanwhile, accused the opposition of fueling the violence. SANA quoted government officials as saying they thwarted a plot by "an armed terrorist group" to enter Syria from Turkey.
Assad has consistently blamed foreign-funded terrorists and thugs for the violence that has engulfed the country since March 2011.
Opposition leaders say at least four people died and 25 people were wounded Thursday in fighting near Deir Ezzor in eastern Syria.
"It is collective punishment because there are some activists [in this area of Deir Ezzor]," an opposition activist identified as Abu Bilal told CNN. "People are trapped in their homes, and the mosques are calling on God for help. The humanitarian situation is bad because we cannot even help our injured. We have no idea if the monitors will visit Deir Ezzor."
The latest reports of violence came after news more U.N. observers were arriving in Syria to monitor the cease-fire. The U.N. Security Council recently authorized deploying as many as 300 monitors to Syria for 90 days.
French Foreign Minister Alain Juppe raised the possibility of outside military force if Assad doesn't fully implement Kofi Annan's six-point peace plan, the Los Angeles Times reported. U.S. Secretary of State Hillary Clinton also has mentioned the possibility of such action.
Annan, the former secretary-general of the United Nations, is acting as a special envoy for the Arab League.
"We'd have to move into a new phase with a Chapter 7 resolution to stop this tragedy," Juppe said.
A Chapter 7 resolution would allow the U.N. Security Council to take action that can include the use of military force.
The United Nations estimates at least 9,000 people have died in protests that began more than a year ago while activist groups put the death toll at more than 11,000.