Supporters of a firebrand Iraqi cleric shot five people dead in overnight clashes with anti-government protesters in southern Iraq, according to medical officials.

The anti-government demonstrators attempted to block the path of a rally supporting Shiite Muslim leader Moqtada al-Sadr.

Iraq Protest
Followers of Shiite cleric Muqtada al-Sadr gather in Tahrir Square in Baghdad (Khalid Mohammed/AP)

Followers of the populist cleric also wounded 40 other people in the clashes, according to two medical officials.

The anti-government demonstrators were camped out in a main square in the city of Nasiriya, which has been an epicentre of the youth-led protest movement that has sought to sweep aside Iraq’s ruling sectarian elite.

Following the clashes, which began on Friday, al-Sadr’s supporters stormed Haboubi Square, and set fire to tents pitched in the square.

Iraq Protest
Thousands took to the streets in Baghdad on Friday in a show of support for radical Iraqi cleric Muqtada al-Sadr ahead of elections scheduled for next year (Khalid Mohammed/AP)

Al-Sadr leads a powerful political bloc in the Iraqi parliament and his supporters had called for a demonstration in support of the leader’s call for mass participation in next year’s nationwide elections.

Anti-government protesters feel betrayed by al-Sadr’s flip-flop approach towards them, especially in the last few months when he withdrew support for their movement.

Dozens returned to the anti-government sit-in’s site on Saturday morning in support of those protesters killed overnight.