Afghan and foreign troops clashed with and called airstrikes on militants in southern Afghanistan, leaving 24 dead and eight wounded, an official said Saturday.

The fighting was in two separate mountainous areas of Zabul province late Friday, said provincial deputy governor Ghulab Shah Alikheil.

The operation was aimed at militants responsible for Tuesday's ambush on a road construction crew in the province that left 17 people killed and 16 others wounded, Alikheil said.

There were no casualties among the joint forces, he said.

Road-building is a key part of Afghan reconstruction and many projects are in remote, insurgency-plagued areas. Militants have targeted work crews in roadside bomb attacks, ambushes and kidnappings, killing and wounding dozens of workers and their private security guards.

On Saturday, a homicide bomber attacked an Indian road construction crew in the southwestern Nimroz province, killing two people, including an Indian engineer, said Gov. Ghulam Dastagir. Eight other people, including five Indian workers and two civilians, were wounded in the blast, he said.

The bomber approached the construction site on foot, the governor said.

The Taliban "are conducting these suicide attacks and terrorist attacks to stop the development and reconstruction in Afghanistan," Dastagir said.

Homicide attacks in Afghanistan spiked in 2007, with the Taliban launching more than 140 suicide missions, the highest number since the radical Islamist group was ousted from power by a United States-led invasion in 2001.

The United Nations says more than 8,000 people were killed in insurgency-related violence in 2007.