Islamabad, Jul 21 - A suicide bomber blew himself up outside the compound of an anti-Taliban militant commander in the tribal belt of northwest Pakistan today, killing nine persons and injuring about 20 others, officials said.

Confusion surrounded the attack, with some accounts suggesting that the bomber approached the compound of commander Maulana Nabi Hanfi in Spin Tal town on foot.

Other reports said the bomber targeted the compound with an explosives-laden vehicle.

The attacker detonated his explosives when he was stopped by guards outside the compound, officials told the media.

Five children playing near the compound and four members of Hanfi's group were among the dead. The compound collapsed following the explosion.

The injured were taken to a hospital in nearby Hangu town in Khyber-Pakhtunkhwa province. Officials said the death toll could rise as some of the injured were in a critical condition.

Officials said the bomber's target was Hanfi's compound.

Hanfi, who escaped unharmed, was once part of the banned Tehrik-e-Taliban Pakistan but parted ways with the organisation after he developed differences with other commanders.

No group claimed responsibility for the attack though officials said they believed it was the handiwork of the Pakistani Taliban.

TTP commander Mullah Toofan is considered Hanfi's main rival. PTI