The Syrian Army bombarded parts of Damascus Thursday, in what the opposition described as revenge attacks for the deaths of three top regime officials, and there was no information on the whereabouts of President Bashar al-Assad, dpa reported. "The army artillery, positioned in Kasyoun (a hill overlooking the capital), has heavily shelled areas where clashes between the military and the revolutionaries have raged in the past five days," said activist Haytham al-Abdallah. Defence minister Daoud Rajha; his influential deputy Assef Shawkat - al-Assad's brother-in-law; and assistant vice president Hassan Turkmani were killed Wednesday in an unprecedented attack in the capital. The fate of Interior Minister Mohammed Ibrahim al-Shaar, who reportedly suffered serious wounds in the bombing of the national security headquarters, remains unclear. Al-Assad has made no statement since the attack, and has not appeared in public. Activists told dpa late Wednesday that the president had moved his family from the capital, shortly after the bombing, to his hometown in Kardaha in the northwest. Within hours of the bombing, for which the opposition Free Syrian Army claimed responsibility, soldiers loyal to al-Assad pounded areas in and around Damascus, killing at least 100 people, according to the opposition. On Thursday, the opposition posted online pictures of people who they claimed were killed by regime forces in Damascus. The fresh violence comes as a divided United Nations Security Council braces for a vote Thursday on renewing the mandate of unarmed military observers, whose three-month term is due to expire. The council is expected to vote on a Western-backed draft resolution threatening sanctions against al-Assad's government. British Prime Minister David Cameron Thursday urged Russia to back the UN resolution as it was time for al-Assad "to go." Cameron, speaking during a visit to Afghanistan, called for the start of transition in Syria. "It is time for him (al-Assad) to go. It is time for transition in the regime. If there isn't transition it's quite clear there's going to be civil war," he said in Kabul.