Peshawar/IBNS: At in least 9 civilians died as suicide bombers belonging to a militant group crashed their explosive-laden cars into an army compound in northwestern Pakistan on Tuesday evening, police told AFP.

"The death count now stands at nine, including three children and two women. At least 20 others were injured in both blasts," a senior police official said on condition of anonymity.

The suicide attack took place at Bannu, a district in Pakistan's turbulent Khyber Pakhtunkhwa province which lies adjacent to the country's formerly self-governed tribal areas, said reports.

"The blasts created two four-foot craters, and due to their intensity, at least eight houses in the locality have been damaged," AFP quoted the police official saying.

"Apart from two suicides, six militants were shot dead in an exchange of fire," he added.

An intelligence official told AFP that 12 militants had attempted to storm the compound after the suicide bombers.

Hafiz Gul Bahadur armed group, which actively supported the Afghan Taliban in its war against the US-led NATO coalition since 2001, claimed responsibility for the attack.

"Our fighters got access to an important target and took control," the group said in a statement, without providing further details.

The attack comes days after a suicide bomber killed six people at an Islamic religious school in Pakistan, attended by key Taliban leaders in the same province.