The blast occurred at a mosque building near police headquarters

A car-bomb attack on a mosque at a police compound in north-western Pakistan has killed at least 21 people and injured more than 100, officials say.

Fifteen police officers and a four-year-old child are among those killed in the suicide attack, which also involved gunmen firing on the police facility in the city of Kohat in the province of Khyber Pakhtunkhwa, Pakistan's APP news agency reported.

Video found by BBC Verify shows the site covered in rubble and people tending to casualties.

Khyber Pakhtunkhwa Police suggested a faction of the Tehrik-e-Taliban Pakistan (TTP), also known as the Pakistani Taliban, carried out the attack.

A car loaded with explosives rammed into the entrance of the mosque at about 13:15 local time (08:15 GMT), police say. Friday prayers were taking place at the time.

At least six of the attackers were killed in the explosion and the gun battle that followed, according to a Khyber Pakhtunkhwa Police spokesperson.

In a post on X, the force said it was "determined to foil the nefarious designs of Fitna-al-Khawarij" - the designation used by officials to refer to the Pakistani Taliban.

The group was set up in 2007 with the aim of enforcing its strict version of Islamic law and is allied with al-Qaeda and the Afghan Taliban.

Pakistan's President Asif Ali Zardari expressed "his best wishes for the swift recovery of those injured in the explosion" in a statement, and called for the "complete elimination" of foreign-backed terrorists.

A UN spokesman said Secretary-General António Guterres "strongly condemns" the bombing and that "attacks targeting civilians and places of worship are unacceptable".

In February, officials accused the Pakistani Taliban of being behind a series of attacks in the country, including the suicide bombing of a Shia mosque in Islamabad in which more than 30 people were killed.

Faisal Karim Kundi, governor of Khyber Pakhtunkhwa, said on Friday the province had endured "immense sacrifices in the fight against terrorism".

Militancy in Pakistan's border areas has risen sharply in recent months, with armed groups targeting the military and police.

Islamabad says militants use Afghanistan as a safe haven to train and plan attacks in Pakistan.

Afghanistan's Taliban government denies the accusation and says militant groups are a domestic problem for Pakistan.