US troops, Sadr supporters clash in Najaf

US troops and Iraqi security forces battled Mehdi fighters, loyal to radical Shiite cleric Moqtada al-Sadr in the holy city of Najaf on Thursday, Qatar-based al-Jazeera satellite channel reported.

Two people, a man and a woman, were killed and five others were wounded in heavy fighting which occurred in central Najaf following the Sadr Mehdi fighters attacked a police station overnight, the channel added.

US helicopters opened fire as they flew over Najaf's vast cemetery. US tanks and armoured vehicles took part in the battles in central holy city, it said, adding heavy gunfire and mortar rounds boomed across the city at around 9:45 am (0545 GMT).

"A significant number of aggressors began attacking the station with heavy machine guns, rocket-propelled grenades, mortars and small arms after an initial attack on the police station around 1:00 am (21:00 GMT Wednesday) was unsuccessful," the US military said in a statement.

Najaf governor Adnan al-Zorfi requested back up from US marines after the main police station was attacked at 3:00 am (23:00 GMT Wednesday) for a second time in two hours, it added.

The fighting comes just days after clashes outside Sadr's home between his militiamen and US troops left one civilian dead and others wounded, including militiamen.

Sadr's office accused US troops of trying to arrest the cleric, but the US military said a marine patrol was attacked by militiamen as it drove by.