Beirut - Syria's army seized a major district on Aleppo's southeastern edges on Monday, putting it in control of 90% of areas once held by rebels in the city, a monitor said. The Syrian Observatory for Human Rights said forces loyal to President Bashar Assad seized the Sheikh Saeed district early on Monday after fierce clashes ongoing since the previous afternoon. "The army is now in full control of Sheikh Saeed," Observatory head Rami Abdel Rahman told AFP."Syrian regime forces are now in control of 90%" of the one-time rebel areas in Aleppo's east, he said.Syria's second city, Aleppo had been divided since 2012 between government forces in the west and rebel groups in the east. In less than a month, a blistering offensive by Syria's army and allied militia has overrun most of rebel territory in the city. Air strikes pounded the remaining opposition-controlled districts of Aleppo through the night and into the early morning on Monday, the Britain-based Observatory said.At least 413 civilians have been killed in east Aleppo since the offensive began on November 15, the Observatory said, and 139 killed in rebel rocket fire on the city's west.And more than 300 000 people have been killed since Syria's conflict first erupted in March 2011.