ISLAMABAD, Jan 3: Pakistan has asked US-led coalition forces in Afghanistan to investigate a border skirmish in which one of its soldiers died and three others were wounded, a military spokesman said on Monday.

Mortar rounds were fired from Afghanistan into Pakistani's rugged North Waziristan region on Sunday, injuring four soldiers, one of whom later died, Major General Shaukat Sultan told AFP.

"We are not sure who fired from the Afghan side, but naturally this could be miscreants," Maj-Gen Sultan said, referring to Taliban and Al Qaeda remnants hiding out in the porous frontier area.

"Since the fire came from Afghan side, an area under the control of coalition authorities, that is why we have asked them to investigate and find out who fired from their side," he added.

North Waziristan faces Afghanistan's Khost province and is located close to the turbulent South Waziristan tribal zone, where thousands of Pakistani troops are currently hunting down foreign and domestic extremists. -AFP