BEIRUT - Syrian forces shot dead four civilians on a bus and fighting raged near Damascus, dissidents said, as international pressure mounted on President Bashar al-Assad to honor UN-backed ceasefire pledges to order his troops back to barracks. In the city of Hama, an anti-Assad hotbed, an explosion ripped through a building, killing at least 12 people and wounding dozens more, according to the UK-based Syrian Observatory for Human Rights. Another activist group, the grassroots Local Coordination Committee, said the blast was caused by a rocket launched into the building and put the death toll much higher at 54, including several children. A third activist source said the explosion may have come from inside the building. It was not immediately possible to reconcile the varying accounts. There was no comment from Syria's government, which says it is committed to U.N.-Arab League peace envoy Kofi Annan's April 12 ceasefire accord, but reserves the right to respond to what it says are continued attacks by "terrorist groups". Hama has been hosting a small team of United Nations observers, who are preparing the way for a larger U.N. mission which will arrive to monitor the ceasefire pact. In defiance of the truce accord, shelling was relentless in Douma, east of the capital, residents said, giving further ammunition to Western states such as France that want broad United Nations sanctions to try to end more than a year of fighting in which 9,000 people have been killed. As well as urging faster deployment of U.N. monitors, French Foreign Minister Alain Juppe said Paris would push for a so-called "Chapter 7" resolution, which would mean punitive sanctions, next month if Assad's forces did not pull back. "This cannot continue indefinitely. We want to see observers in sufficient numbers, at least 300 ... deployed as quickly as possible," Juppe said. "If that does not work, we cannot allow the regime to defy us. We would have to move to a new stage with a Chapter 7 resolution at the United Nations to take a new step to stop this tragedy." The Syrian Observatory for Human Rights said four people were killed when security forces opened fire on a bus at a checkpoint on the main road from Aleppo to Damascus. An elderly man was also killed, it added, in heavy fighting in the southern city of Deraa, crucible of the anti-Assad revolt that flared 13 months ago after uprisings against autocratic leaders in North Africa and the Middle East. A woman who visited Douma on Tuesday night said the town had been under constant shelling and was without water, power or mobile phone signal. Pro-government gunmen were wandering the streets, she added, preventing people from leaving their homes.
