As many as 31 Syrian inmates have been killed over the past two weeks due to the rebels\' bombardment on the central prison of Syria\'s northern Aleppo city, the Britain- based Syrian Observatory for Human Rights said Friday. The rebels have besieged the prison earlier this month when they blew up two car bombs to break the government troops\' siege. However, their attempt to storm the facility and take over it has been a failure so far. The dead prisoners were buried in one of the prison\'s yards, the Observatory said, adding that the prolonged fighting for controlling the prison has claimed the lives of 40 government soldiers. Separately, the Observatory claimed that 19 men from the capital Damascus\' suburb of Qatana were tortured to death in government-run detention centers. Meanwhile, Syria\'s state-run SANA news agency said the Syrian troops on Friday carried out operations against armed opposition fighters in Aleppo countryside, killing and injuring many of them in the industrial city in al-Sheikh Najar area and the areas surrounding Minnegh airbase and the central prison. Army units clashed with armed groups in the vicinity of Aleppo\' s central prison in al-Maslamyeh area and destroyed their dens, SANA said, adding that 12 rebels were killed near a cemetery and a gas station in the countryside of Aleppo.