Groups of men residents and activists described as ' Assad death squads ' stormed several neighborhoods in Homs Thursday firing machines guns and pulling people from their homes in a series of arrests., the AFP reported. Smoke reportedly billowed from at least one area in Homs, which has experienced some of the most intense and sustained violence in recent days as President Bashar Assad seeks to crush a more than four-month-old popular uprising. A resident, who spoke on condition of anonymity fearing government reprisals, said Bab Sba'a has been subjected to heavy machine-gun fire since 4am. "I can see smoke billowing from the neighborhood," the man said by telephone as heavy gunfire could be heard in the background. "We cannot leave our homes." The Local Coordination Committees, which help organize and document the protests in Syria, says troops were bombarding residential streets in Bab Sba'a with tanks and machine guns. The LCC said casualties occurred in the raids, but the gunfire was too intense for people to collect the victims from the streets. It also said that some army soldiers defected and were shooting back at troops firing at civilian areas. One home was reportedly burned by Assad troops and telecommunications had been cut in parts of the city. Up to 50 people have been killed in Homs since the latest chapter in Assad's bloody crackdown, activists and witnesses say. The regime has banned nearly all foreign media and restricted media coverage, making it nearly impossible to independently verify casualty figures. Syria has come under withering international criticism and sanctions for its crackdown, which activists say has killed some 1,600 people, most of them unarmed protesters. The pro-Assad Al Watan daily claimed the situation in Homs is calm despite cracks of gunfire heard in some streets in the city.