Assad side kills four at Syrian university: protesters The pre-dawn raid was an unusually bloody incident for Aleppo, Syria's normally fairly peaceful commercial hub, and prompted condemnation from the White House. Washington accused Assad of making "no effort" to honor a three-week-old United Nations truce and warned that world powers might do more to bring change to Syria if the ceasefire plan brokered by envoy Kofi Annan failed. "If the regime's intransigence continues, the international community is going to have to admit defeat and work to address the serious threat to peace and stability being perpetrated by the Assad regime," White House spokesman Jay Carney said. Political transition is urgently needed in Syria. Western powers back the 14-month revolt but lack appetite for the kind of military intervention seen last year in Libya. Assad has counted on support from Russia and China to block United Nations sanctions. However, Moscow and Beijing backed the ceasefire plan and Western states may hope to persuade them to agree to penalize Assad if it collapses. On Thursday, however, the head of the monitoring mission sent to Syria under the plan said the team of U.N. observers in the country was having a calming effect. A Reuters team in the opposition centre of Homs during the day heard continuous gunfire and the occasional sound of shelling, despite a permanent presence of monitors there. Opposition figure Fayez Sara said secret police had raided the homes of his sons Bassam and Waseem on Thursday, continuing the detentions of tens of thousands since the uprising began. I have no idea where they have been taken. Bassam is 37. Waseem is 26," said Sara. The Syrian Journalist Federation, an independent organization, also called for the release of Mazen Darwish, a free speech campaigner who has not been heard of since security police took him from his Damascus office two months ago. Video posted on the Internet showed students in Aleppo chanting against four decades of Assad family rule but being drowned out by gunfire. Activists posted images of a dead student, drenched in blood, and what they said was a burning dormitory. Assad says he is fighting foreign-backed "terrorists" and his international friends, including in Moscow, point out that rebels too have staged attacks in breach of the ceasefire. The truce has led to a small reduction in the daily carnage, mostly in cities were monitors are deployed permanently. Mood, who is from Norway, told reporters during a trip to Hama on Thursday that state forces appeared willing to cooperate with the truce. Clashes between rebels and the army also flared in Palmyra, home to historic Roman ruins in central Syria. Mood, speaking in Homs later on Thursday, said that observer mission was growing at a steady pace, with a total of 50 monitors in the country which would be doubled within weeks. In Washington, the White House spokesman expressed doubts about whether the truce would hold. "It is certainly our hope that the Annan plan succeeds," Carney said. We remain, based on the evidence, highly skeptical of Assad's willingness to meet the conditions of that plan, because he has so clearly failed to meet them thus far. Syria's news agency said another state figure, national basketball team player Bassel al-Raya, died of his wounds on Thursday after being attacked by unidentified gunmen a week earlier. The U.N. says more than 9,000 people have died in the crackdown, while the Syrian government says it has lost at least 2,600 of its forces to "foreign-backed terrorists." Despite the turmoil, Syria plans to hold a parliamentary election on Monday under a new constitution which has allowed the creation of new political parties and formally ended decades of monopoly by Assad's ruling Baath Party. Additional reporting by Mariam Karouny in Homs, Dominic Evans and Oliver Holmes in Beirut and Laura MacInnis and Matt Spetalnick in Washington; Editing by David Stamp and Alastair Macdonald