Image caption The Taliban remain strong in North Waziristan

Up to 700 people in a tribal region of north-west Pakistan watched the Taliban publicly execute a man accused of killing two brothers, officials say.

Masked militants shot the man, blindfolded and bound, dead at a football ground in Miranshah, the main town in North Waziristan.

Militants in Pakistan's tribal areas have killed scores of people accused of spying for the US in recent years.

But such public executions by the Taliban are rare.

The BBC's M Ilyas Khan in Islamabad says that the latest execution highlights the power the Taliban wields in the region and reflects the growing power and confidence of the militants.

'Quick justice'

Our correspondent says that the security forces appear to have been powerless to stop the execution from taking place.

The killing also signifies an effort by the Taliban to win local people's sympathy by delivering quick justice, our correspondent says.

Locals in Miranshah told the BBC that the man who was killed, known only as Waheed, was 25.

They said two masked militants opened fire on him, killing him on the spot. He had earlier been found guilty by a self-styled Taliban "court".

A government official said that the body of the dead man was found near the town, along with a letter that named him and said he had been executed on the orders of a Taliban council for killing two brothers, Noor Zeb and Alam Zeb.

Local sources say Waheed opened fire on his two brothers in Miranshah's cycle ground area after a brief altercation last month.

There have been instances of public Taliban "justice" in the area before, but they are not common.

In December 2005, the Taliban in Miranshah clashed with a local militia led by Hakim Khan. His group had set up checkpoints in the area and were extorting money from motorists, traders and residents.

Both sides suffered casualties, but eventually the Taliban killed him and nearly 24 of his men. They were condemned as robbers and extortionists and their bodies were left hanging from trees.

The Pakistani army has launched several offensives in the volatile north-west over the past year, killing hundreds of militants and capturing several of their strongholds.

But it has resisted US pressure to launch an offensive in North Waziristan.