At least 31 people were killed when Pakistan Taliban attacked a pro-government militia, according to reports from the two sides on Saturday, but the Taliban were beaten back after hours of fierce fighting.

About 300 Taliban armed with mortars and rocket-propelled grenades launched the overnight assault in the Maiden area of Tirah, a maze of valleys on a route from Afghanistan to the city of Peshawar, a fighter of the pro-government Ansar ul-Islam militia said. 

The militia beat the Taliban back, killing 15 and capturing 8, while three villagers, including an elderly woman, were killed in crossfire, he said. 

A Taliban fighter said they killed 13 members of the pro-government militia.

Since 2009, the Pakistani military and pro-government militias have been clawing back territory from the Taliban, who once controlled land a few hours' drive from the capital of Islamabad. 

Pakistani government officials say the NATO withdrawal of troops from Afghanistan in 2014 might strengthen the Taliban in Pakistan. The Afghan and Pakistani Taliban are separate groups but strong allies.