At least 55 people were killed Friday, March 2, in violence in Pakistan's troubled northwestern tribal region of Kyhber, which borders Afghanistan, local officials said.

According to AFP, 22 people were killed in a suicide attack targeting a mosque after Friday prayers in the Tirah valley, while at least 10 soldiers and 23 Islamist militants died in an earlier clash around 10 kilometers away (six miles).

Kyhber is a haven for militants linked to the Pakistani Taliban and the threat of renewed fighting there between the army and insurgents prompted some 18,000 people to flee their homes in October last year.

Local administration official Jamilur Rehman told AFP that the suicide blast killed at least 22 people and wounded more than 20 others, adding the toll may rise.

"The bomber detonated himself near the gate of a mosque in Tirah valley of Khyber tribal region when people were returning from the prayers," he said.

The mosque is located in an area controlled by warlord Mangal Bagh, he said, adding that most of the dead were from his Lashkar-i-Islam - a group widely linked to militants and criminal gangs.

The attack and the toll was confirmed by Khyber administration chief Mutahir Zeb Khan. "It was a suicide attack. The bomber blew himself up at the entrance of the mosque when the worshippers were returning after the Friday prayers," he said.

Khan earlier said at least 10 Pakistani soldiers and 23 militants were killed in a gunfight in the Tirah valley.

Islamist militants have killed more than 4,900 people across Pakistan since government troops raided an extremist mosque in Islamabad in July 2007.

Separately, gunmen on motorbikes Friday shot dead an intelligence official in the northwestern city of Peshawar, the capital of restive Khyber Pakhtunkhwa province which borders Afghanistan, police said.