Taliban gunmen killed at least nine Pakistani policemen in twin attacks overnight in a northwest tribal district that borders Afghanistan, officials said on Thursday.

Two separate groups of militants struck almost simultaneously at a police checkpoint in the Pandyali area of Mohmand district where they killed seven, and at a solar-powered tube well in Michni area of the same region where they shot dead two police who were standing guard.

‘The attacks came at around 1:00 am (8:00 GMT). It was pitch black and the policemen were caught unaware. The militants struck suddenly and killed them without giving them a chance to fight back,’ Naveed Akbar, an administration official in the region, told AFP.

Akbar said that the attackers also torched the police post and destroyed the tube well.

Another senior administration official, Mehmud Aslam, confirmed the incidents, which were later claimed by the Jamaat-ul-Ahrar faction of the Tehreek-e-Taliban Pakistan (Pakistani Taliban) militant group in an email sent to AFP.

Mohmand is one of Pakistan's seven tribal districts which border Afghanistan and have been home to Al-Qaeda and Taliban led militants.

Pakistan's army intensified its offensive in the region after the Taliban's massacre of 153 people, mostly children, in Peshawar in December 2014, and killed or pushed hundreds of militants to Afghanistan.

Overall, levels of militant-linked violence have dropped dramatically, with 2015 seeing the fewest deaths among civilian and security forces since 2007 -- the year the Pakistani Taliban umbrella group was formed.

But the threat posed by the Taliban remains, particularly in the country's northwest.

Last month Taliban gunmen stormed a university in the northwestern town of Charsadda, killing 21 people in a chilling reminder of their ongoing ability to carry out occasional high-profile and brazen attacks.

Pakistan's Islamist insurgency began after the US-led invasion of neighbouring Afghanistan in 2001, which led to a spillover of militants across the border and a surge in recruitment for Pakistani extremist groups.