Kabul, Afghanistan ? Two Taliban ambushes of civilian convoys left 30 people dead, while coalition and Afghan forces killed at least 11 militants in an ongoing U.S.-led offensive across southern Afghanistan, officials said Monday.

More than 10,000 coalition and Afghan troops are fanning out across four volatile southern provinces to combat Taliban militants launching attacks from towering mountain ranges. They have been responsible for the deadliest violence since the extremist regime was toppled in 2001 by a U.S.-led invasion force.

But despite Operation Mountain Thrust, the bloodshed has continued. Early Sunday, a former district chief in Helmand province, Jama Gul, was killed along with his four bodyguards on the highway outside of Sangin district, relatives and officials said.

Hours later, militants ambushed a convoy carrying about 40 of the slain official’s relatives who were traveling to collect his body, killing 25 people and wounding four.

In separate clashes, Afghan and coalition soldiers killed 11 militants in Uruzgan and Zabul provinces, where Mountain Thrust is being conducted, Afghan officials said.