At least 17 people have been killed and 73 others woundedafter a vehicle laden with explosives rammed into a mosque in north-western Pakistan, according to Pakistan's news agency.

Seven police officers and a four-year-old child are among those killed in the attack, which also involved gunmen opening fire within a police facility in the city of Kohat in the province of Khyber Pakhtunkhwa, the Associated Press of Pakistan (APP) reported.

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

Pakistan's President Asif Ali Zardari expressed "his best wishes for the swift recovery of those injured in the explosion" in a statement.

The blast is reported to have occurred around 13:15 local time (08:15 GMT) while Friday prayers were taking place.

Khyber Pakhtunkhwa police Insp Gen Zulfikar Hameed described it as a "suicide attack", according to news agency Reuters, which also reported that police had confirmed all seven attackers had been killed in the explosion and the gun battle that followed.

A police spokesperson said the seven armed militants attempted to infiltrate the police facility following the blast, according to the APP.

No group has immediately claimed responsibility for the attack.

Prime Minister Muhammad Shehbaz Sharif condemned the blast.

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.