United Nations, Aug 20 (IANS): UN Secretary-General Ban Ki-moon has condemned in the strongest terms the suicide attack at a mosque during Friday prayers in Pakistan where at least 50 people were killed.

"The secretary-general is appalled at this deliberate attack at a place of worship during the Muslim holy month of Ramadan, and the reported use of a teenager to perpetrate the attack," Xinhua quoted Ban as saying in a statement.

Over 50 people were killed and more than 125 were injured when a teenaged suicide bomber blew himself up inside a packed mosque in Ghondi area of Jamrud district of Khyber Agency bordering Afghanistan.

Reports said there were about 400 people in the mosque, which partially collapsed following the explosion.

The UN chief said: "The UN continues to stand by Pakistan in its efforts to combat the scourge of terrorism."

The secretary-general also extended his heartfelt condolences to the families of the victims and the government of Pakistan.