At least seven people were killed in a skirmish between Taliban forces and militia fighters in the Panjshir valley north of Kabul on Monday night, according to two members of the largest anti-Taliban opposition party.

Panjshir has been the sole province to hold out against the Taliban after the fall of Kabul on Aug. 15, despite combat between Taliban and local militia forces in nearby Baghlan province.

The combat took place on the western entrance to the valley, where the Taliban attacked NRF positions, according to Fahim Dashti, a spokesman for the National Resistance Forces, a militia loyal to local commander Ahmad Massoud.

According to him, the attack, which may have been a ruse to test the valley's defenses, was rebuffed, with eight Taliban dead and a comparable number injured, as well as two NRF personnel wounded.

In a tweet, Bismillah Mohammadi, a member of the resistance movement who served as a minister under exiled President Ashraf Ghani, said, "Last night, the Taliban attacked Panjshir, but were defeated with 7 dead and several wounded,"

"They retreated with heavy casualties."

A Taliban spokesman could not be reached for comment right away.

Massoud, the son of former anti-Soviet mujahideen commander Ahmad Shah Massoud, has amassed a force of tens of thousands in the Panjshir valley, made up of local militias and army and special forces remnants.

He has advocated for a political settlement with the Taliban but has warned that if his province in the small and hilly valley is invaded, his army will fight back.

Although a large force of Taliban fighters has been deployed to the area, the two sides have so far avoided fighting by engaging in negotiations.

On Tuesday, celebratory gunfire rang out throughout Kabul as Taliban insurgents took control of the airport following the departure of the final American troops, signaling the end of a 20-year conflict that left the Islamist militia stronger than it was in 2001.