US helecopter was shot down Thursday in Iraqi holy city of Najaf, Qatar-based al-Jazeera TV channel reported.

The helicopter was shot down near gas station in the cemetery area, al-Jazeera said.

The US military spokesman confirmed the incident, saying several members of the crew were wounded, without giving further details about it.

Iraqi police and security forces baked by US troops fought a fierce battle against militiamen loyal to radical Shiite cleric Moqtada al-Sadr in the city of Najaf.

US helicopters opened fire as they circled above Najaf's vast cemetery and US tanks and armoured vehicles took part in the battles in the centre of the holy city.