US troops release Iraq official

Ammar al-Hakim, the son of Abdul Aziz al-Hakim, was arrested at a border checkpoint as he returned from Iran, security and Shia officials said.

It remains unclear why Mr Hakim and his two bodyguards were detained.

The US ambassador to Iraq apologised and said that the circumstances of the detention would be investigated.

Mr Hakim, a cleric, was arrested near the Mehran border crossing with Iran, 130km (70 miles) east of Baghdad.

'No disrespect'

Washington did not mean any disrespect to Mr Hakim or his family, US ambassador to Iraq Zalmay Khalilzad said.

"I am sorry about the arrest," he said. "We don't know the circumstances of the arrest and we are investigating ... but he is being released."

US military spokesman Lt Col Christopher Garver said security forces would release more information "as it becomes available".

Mr Hakim and his bodyguards were reportedly taken to a US base where they were held for most of the day before Mr Hakim's release.

Political dynasty

Abdul Aziz al-Hakim is the leader of the largest party in Iraq's parliament, the Supreme Council for the Islamic Revolution in Iraq (SCIRI).

SCIRI is planning large demonstrations in Najaf to protest against Mr Hakim's detention, the BBC's Adi Raval says in Baghdad.

The party was founded in 1982 by Abdul-Aziz al-Hakim's brother Mohammed Bakr al-Hakim in Tehran.

Abdul Aziz al-Hakim took over the party when Mohammed Bakr was killed in an al-Qaeda car bombing in August 2003.

Correspondents say he is seen as close to US President George W Bush, whom he met last year. He also has links to Iran, where he lived for years in exile.

Ammar al-Hakim heads the Al-Mihrab Martyr's Foundation, in honour of his uncle, and is seen as the deputy leader of the political movement.

Last December, the Hakim residential compound in Baghdad was raided by US forces who arrested two Iranians said to be members of the Iranian Revolutionary Guard.