Blast heard in Iraqi city of Najaf

NAJAF, Iraq, Apr 6 (Reuters) A blast was heard today in Iraq's southern Shi'ite city of Najaf and ambulances were heard rushing to the scene, residents said.

There was no immediate word on the cause of the explosion.

Najaf is home to the most sacred Shi'ite shrine. Mostly Shi'ite southern Iraq has been relatively free of the Sunni insurgent violence gripping central Iraq but rivalries among Shi'ite groups with militias have been growing.

REUTERS OM HT1610