Iraqi security forces continued to clash with anti-government protesters in Baghdad on Sunday, just a day after a violent police operation left six demonstrators dead and more than 100 injured.

Protesters ran away as live ammunition, tear gas canisters and stun grenades were fired towards them.

Security forces put up concrete barriers in the centre of the capital, trying to hamper and block protesters' movements.

Since the unrest began last month, more than 260 protesters have been killed by security forces.

Amnesty International called it a "bloodbath" and said Iraqi authorities should immediately rein in security forces.

The growing security crackdown reflects the government's intransigence and narrowing of options for protesters taking to the streets of Baghdad and the Shi'ite-dominated southern cities for weeks.

Authorities blocked the Internet and banned social media several times amid protests.

The unchallenged protests, driven by deteriorating economic conditions, target the entire Iraqi political class and call for reform of the sectarian system created after the US-led invasion in 2003.

Protesters are demanding the resignation of Prime Minister Adel Abdel Mahdi's government, which has held the post for more than a year. But he refused to step down.