A suicide bomber attacked the funeral service Thursday of a Pakistani tribesman opposed to the Taliban, killing 31 people, police said, two days after Taliban gunmen killed four children from another district in conflict with the militant network.

The blast during the ceremony in the Lower Dir region, 15 miles (25 kilometers) west of the Afghan border, wounded 75 people.

The bomber struck as around 200 mourners were attending the funeral in the Shina Samar Bagh village, police officer Sher Hassan Khan said.

Another police officer, Salim Marwat, said the attacker hid in a nearby field and then ran toward the graveyard shouting "Allah Akbar!" -- the Arabic phrase meaning "God is Great" that is also a Muslim rallying cry -- and then detonated his bomb.

Witness Gull Rehman said he saw the attacker, who was killed in the bombing, describing him as a man with a long beard. Rehman said he was knocked down by the blast but he was able to get up and help transport the injured to hospitals.

Later, police officers searched for parts of the bomb on the blood-soaked field, strewn with abandoned sandals.

The funeral was for Bakhat Khan, who was a member of a local "lashkar" or militia that is opposed to Taliban rule in the region, police said. He died Wednesday night.

The tribesmen in the northwest have formed several such militias, for which they typically receive some government funding. They have had some success at stopping militant infiltration but are routinely struck by revenge attacks.

Many of the bloodiest bombings of the last three years have targeted "lashkar" members or their families.

On Tuesday, Taliban gunmen killed four children as they were returning from school close to the main northwestern city of Peshawar. The insurgents said the attack was aimed at stopping locals there supporting a tribal militia that is fighting them.

Around 35,000 people have been killed in militant violence in Pakistan since it began in earnest in 2007.