PESHAWAR - At least 55 people were killed yesterday in violence in Pakistan's troubled northwestern tribal region of Kyhber, which borders Afghanistan, local officials said. Twenty-two 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 10km 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 reporters 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. "At least 10 soldiers embraced martyrdom and three others were wounded," a senior security official told reporters, adding that the fighting lasted for nearly six hours. "All law enforcement agencies' posts in the area were intact and the situation was stable," the official said, blaming the Lashkar-i-Islam group for attacking the outpost. Military officials in Peshawar confirmed the attack and casualties, but it was not possible to independently verify the official account of the incident as access to the area is restricted by the military. Pakistan's seven tribal districts near the Afghan border are rife with homegrown insurgents and are strongholds of Taliban and al-Qaeda operatives. 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 yesterday shot dead an intelligence official in the northwestern city of Peshawar, the capital of restive Khyber Pakhtunkhwa province which borders Afghanistan, police said. Bashir Khan, a 38-year-old Intelligence Bureau inspector, was on his way to work on his motorcycle when gunmen also riding a motorbike shot him, senior police official Tahir Ayub told reporters. Ayub said it was not immediately clear who shot Khan, but Taliban militants have previously attacked and killed intelligence officials in the area. Peshawar has a population of 2.5 million people and has long been on the frontline of violence blamed on a five-year insurgency led by Taliban militants opposed to Islamabad's alliance with the United States.