At least 32 people have been killed and 150 injured in an explosion at a mosque in the Pakistani city of Peshawar.
Part of the building was destroyed, and officials say people are buried under the debris.
Most of the dead were police officers and are believed to have been targeted.
Earlier reports said a terrorist sitting in the front row had detonated, but this has not been confirmed and no group has claimed responsibility for the attack.
Peshawar Police Chief Muhammad Ijaz Khan told local media that between 300 and 400 police officers were in the area at the time of the blast.
Prime Minister Shehbaz Sharif strongly condemned it. In his statement, he said that those behind the incident “have nothing to do with Islam.”
He added: “The entire nation is united against the threat of terrorism.”
The blast occurred around 1:30 p.m. (08:30 GMT) during afternoon prayers in the northwestern city, near the country’s border with Afghanistan.
A video posted on social media and confirmed by the BBC shows half the wall has collapsed. The mosque is covered in bricks and debris as people climb over the debris to escape.
A rescue operation is underway in the mosque, and “more bodies are being taken out,” said Peshawar Deputy Commissioner Shafiullah Khan.
“Our priority right now is to rescue people buried under the debris,” Mr Khan added.
Mohammad Asim, a spokesman for Lady Reading City Hospital, said some of the injured were in a critical condition.
“This is an emergency,” added Mr. Asim.
Lady Reading Hospital declared a state of emergency and told the BBC they were still accepting victims of the blast and appealing for blood donations.
The Prime Minister went to Peshawar on an emergency visit, where he will receive a briefing from local officials and visit the injured in the blast.
The Pakistani Taliban is one group that has carried out attacks in the past. They ended a ceasefire in November and have seen an increase in violence since then.
In March last year Peshawar became the object of another explosionwhich killed dozens of people in a Shiite mosque.
In the capital Islamabad, the police announced an increased level of security and reported that security at all points of entry and exit to the city had been increased.
