An AFP correspondent at the scene reported volleys of gunfire from behind concrete barricades where security forces were deployed.

The capital's historic Rasheed Street and its nearby colonnaded alleys where riot police have clashed with demonstrators has become a major flashpoint.

Young demonstrators donned helmets and medical masks to face off with security forces unleashing tear gas.

In southern Iraq, protesters sealed off streets with burning tyres as schools and public offices stayed shut a day after anti-government rallies descended into bloodshed.

For nearly two months, the capital and Shiite-majority south have been gripped by the largest protests since the 2003 US-led invasion that toppled Saddam Hussein.

The street violence has left more than 350 people dead and around 15,000 wounded since the start of October.