BAGHDAD (Reuters) - Clashes between rival Shiite militias in the southern Iraqi city of Basra broke out on Wednesday night and continued until Thursday morning, causing casualties, local security officials said. The skirmishes are the latest in violence in the country within a political crisis between supporters of the cleric Muqtada al-Sadr and parties and paramilitary groups mostly allied with Iran. Security officials said the clashes took place in the center of Basra, Iraq's main oil production hub. They did not immediately confirm any death toll from the violence