KABUL, Afghanistan — The Taliban ambushed a peace convoy in western Afghanistan and abducted 26 activists, members of a peace movement, a police spokesman said Wednesday.

The insurgents staged the ambush in the district of Bala Buluk in Farah province on Tuesday. The Taliban forced the six-vehicle convoy to a halt, then got into the cars and drove them and the activists to an unknown location, said the provincial police spokesman Mohibullah Mohib.

According to Mohib, a police operation is underway to locate and free the activists whose convoy was going village-to-village to rally for peace.

However, Bismillah Watandost of the People's Peace Movement of Afghanistan, to which the activists belong, said that 27 of their members were abducted by the Taliban in the Farah assault. The different figures could not immediately be reconciled.

The Taliban, who have been active in Farah, have not claimed responsibility for the abductions. However, Watandost also said that tribal elders in the province immediately launched an effort to negotiate with the Taliban to release the abducted activists. He added that phone lines were down in the region, making communication and getting information from the area difficult.

The Taliban today hold sway or control practically half of Afghanistan and are at their strongest since the 2001 U.S.-invasion. They continue to stage near-daily attacks targeting Afghan and U.S. forces, as well as government officials — even as they hold peace talks with a U.S. envoy tasked with negotiating an end to the 18-year conflict, America's longest war.

The latest rallies by the activists from the People's Peace Movement of Afghanistan started on Friday, first in southern Helmand province, a Taliban heartland.

At a similar series of peace rallies in October, the Taliban abducted six activists from the movement in eastern Logar province but released them the same day.