PESHAWAR, Pakistan -- A Taliban suicide bomber attacked the headquarters of a rival group Friday in northwest Pakistan, killing at least five fighters in the second such bombing this month, militants and a government official said.
Clashes among insurgents are common along the Afghan border, where tribal loyalties hold sway and the government has little or no control. The militants are often competing over proceeds from smuggling, kidnapping and drug production.
Over the last year, the Pakistani Taliban and Lashkar-e-Islam have been battling for control of the Tirah Valley, a remote part of the Khyber tribal region where Friday's attack occurred. The two bombings this month indicate an escalation of that fight.
Pakistani security forces also have been battling the militants in Tirah, who threaten the nearby city of Peshawar.
The bombing killed at least five members of Lashkar-e-Islam, said Bakhtiyar Khan, a government administrator in Khyber.
Hazrat Omar, a spokesman for the group, told The Associated Press by telephone from an undisclosed location that six fighters and two passers-by died.
Mohammed Afridi, a Pakistani Taliban spokesman in Khyber, claimed responsibility for the attack in another phone call with the AP.
A Taliban suicide bomber carried out a similar attack on Lashkar-e-Islam's headquarters on March 2, killing 23 militants. The Taliban said at the time that the bombing was in revenge for an attack last month that killed members of the group.
The Pakistani Taliban is one of Pakistan's deadliest militant groups, and has links to al-Qaida and insurgents fighting across the border in Afghanistan. Its commanders are based in the border region, but the group has allied networks throughout the country.
Security forces have launched offensives in many border regions over the last four years, losing hundreds of men and killing thousands of alleged militants. But attacks still occur regularly in the country.
A bomb hidden inside a radio exploded on a military base in northwest Pakistan on Thursday, killing a paramilitary soldier and his 10-year-old son as they were listening to the Asia Cup cricket final between Pakistan and Bangladesh, intelligence officials said.
Three other children were wounded in the attack at a base in Wana, the main town in the South Waziristan tribal area, a key Pakistani Taliban stronghold that was targeted in a large military offensive in 2009, the officials said Friday, speaking on condition of anonymity because they were not authorized to talk to the media
Authorities are investigating how the bomb was planted in the radio.
Associated Press writer Ishtiaq Mahsud contributed to this report from Dera Ismail Khan, Pakistan.