PESHAWAR: At least 15 people were killed and several injured Friday in a suicide attack on a seminary and mosque in Peshawar, officials said.

Superintendent of Police Rural Shafiullah Khan said the suicide bomber detonated his explosives in the mosque when worshipers were offering Friday prayers.

"One of the attackers wearing a suicide vest entered the mosque and blew himself up in front of the worshipers,” said Khan.

He said three attackers tried to enter the Hussaini madressa in Chamkini area but faced resistance by the security personnel posted at the entrance. He said two attackers were prevented from entering the complex while one managed to enter the Imambargah after the guards were gunned down.

Bomb Disposal Squad official Abdul Haq told Dawn.com that six to seven kilograms of high intensity explosives and four kilograms of pellets were used in the blast.

A loud blast was heard while the Friday sermon was underway at the Imambargah, which was preceded by gun firing, according to eyewitness accounts.

Eye witness Khadim Hussain told that he was inside the mosque when he heard gunfire followed by a huge explosion shattering the windows and the front canopy of the mosque.

Other eyewitnesses said that the attacker shot at the guards posted at the entrance of the complex before entering the premises where the explosives were detonated.

The complex comprises of a madressa and an Imambargah belonging to the Shia sect.

Khyber Pakhtunkhwa Information Minister Shauakat Yousafzai told reporters at the hospital that 14 people were killed while at least 30 were wounded from the deadly blast.

Officials at the Lady Reading Hospital said four bodies and at least 30 wounded had been taken to the hospital. Several of the wounded were reported to be in critical condition.

Prime Minister Nawaz Sharif condemned the incident and the loss of innocent lives while ordering immediate treatment of the victims.