Blast heard near Shi'ite shrine in Iraq's Basra

BASRA, Iraq, Feb 26 (Reuters) A loud explosion was heard today near a Shi'ite shrine in the southern Iraqi city of Basra, witnesses said.

It was not immediately clear what caused the explosion, which came amid raging sectarian violence in Iraq.

Basra, Iraq's second largest city, lies in the mainly Shi'ite Muslim south but around a third of its population is Sunni.

The blast came shortly after firebrand Shi'ite cleric Moqtada al-Sadr held a rally in Basra calling on Sunnis and Shi'ites to hold joint prayers on Friday. It was not clear if he was near the site of the blast.

Reuters OM BD1515