PESHAWAR — At least 32 people have been killed in an explosion at a mosque in the Pakistani city of Peshawar.

The blast happened when the mosque was packed with worshippers and more than 150 people were injured.

A section of the building was destroyed, and officials say people are buried under the rubble.

The cause of the explosion is unclear, but an official said police had been the target and most of those who had died were part of the police force.

Prime Minister Shehbaz Sharif has strongly condemned it. In a statement, Sharif said those behind the incident "have nothing to do with Islam".

He added: "The entire nation is standing united against the menace of terrorism."

The blast took place during afternoon prayers in the north-western city, around 13:30 (08:30 GMT), near the country's border with Afghanistan.

A video circulating social media and verified by the BBC shows that half of a wall has caved in. The mosque is covered in bricks and debris as people clamber over the rubble to escape.

A rescue operation is ongoing inside the mosque and "more bodies are being taken out," Peshawar city deputy commissioner Shafiullah Khan said.

"Currently our priority is to save people buried under the debris," Khan added.

Mohammad Asim, a spokesman for the Lady Reading Hospital, said that some of those injured were in a critical condition.

"It's an emergency situation," Asim added.

Lady Reading Hospital in Peshawar declared an emergency, and they told the BBC they were still receiving those injured during the explosion - and are calling for blood donations.

Last March, Peshawar was the target of another bombing, which killed dozens in a Shia mosque.

In the capital, Islamabad Police issued a security high-alert and said security at all entry and exit points to the city had been increased. — BBC