At least 150 Syrian soldiers were killed this week in a rebel attack that leveled the main buildings at a large base outside Damascus, one of the single highest death tolls of government troops since the start of the armed uprising, according to military and security personnel with knowledge of the assault.

A Syrian military spokesman confirmed earlier rebel accounts that they had tunneled under the buildings for months, then filled them with explosives and blew them up on Sunday.

On Thursday, efforts to clear wreckage from the collapsed buildings on the edge of the rebel-controlled town of Harasta were impeded by heavy sniper and rocket fire from insurgents holed up inside the town, according to the Syrian army spokesman, an opposition activist and fresh videos posted on the Internet by the rebel group that claimed the attack.  […]