Afghanistan, April 21 -- Gunmen abducted four road workers in northwest Pakistan, triggering a search operation and raising fresh concerns over security in a volatile region.

Armed men abducted four workers involved in a road construction project in Tirah Valley in Pakistan, local sources said on Monday.

The workers were reportedly leveling land for a road project when gunmen attacked, threatened them at gunpoint and took them to an unknown location.

Security forces have launched a search operation in the area, but no official details have been released about the identity of the attackers or the fate of the abducted workers.

Khyber Pakhtunkhwa has witnessed a surge in militant attacks in recent months, particularly in tribal districts b...