Insurgents fired rocket-propelled grenades and heavy machine guns into a convoy carrying goods to the Afghan capital on Monday, killing three drivers and wounding two others, an official said. Two of the container trucks caught fire and burned from the grenade blasts at about 2:30 a.m. on the main highway about 60 kilometers (37 miles) east of Kabul, said Sarhadi Zwak, spokesman for Laghman province where the attack took place, according to AP. It was unclear if the trucks were carrying supplies for the U.S.-led military coalition or if they had commercial goods, Zwak said, but he added that no international troops or military vehicles were in the convoy. He said the drivers were Afghan.