Fresh clashes between Iraqi security forces and anti-government protesters broke out on Friday killing at least three people, despite a call for calm by the country's top Shi'ite cleric.
Security forces fired tear gas and threw stun grenades into crowds of demonstrators wearing helmets and makeshift body armour on a main road in central Baghdad, sending protesters scattering, some wounded.
One protester was killed by a tear gas canister fired directly into his head, a witness said.
In the southern city of Basra, two people were killed as security forces dispersed hundreds of demonstrators outside the local government headquarters, police and medics said.
Earlier on Friday Iraqi explosives experts detonated a bomb under a bridge in Baghdad that has been witnessing daily anti-government protests, state TV reported.
The report gave no further details about the controlled detonation under the Sinak bridge, which is one of four crossing the Tigris River into the Green Zone in western Baghdad where government ministries, the parliament building and foreign embassies are located.
The bridges have become the front line between protesters and security forces in the anti-government demonstrations in the capital. At least four protesters were killed by live ammunition at the Shuhada bridge on Thursday.
More than 260 people have been killed in a security crackdown on protests in Baghdad and southern provinces since October 1. The protesters are demanding political reforms and the removal of the political class that they say is corrupt, inept and beholden to foreign powers.
Iraq's top Shiite cleric on Friday called on the security forces to avoid violence against the protesters and urged the government to respond as quickly as possible to their demands.
"The biggest responsibility is on the security forces," Grand Ayatollah Ali Al Sistani said in a sermon delivered by his a representative after Friday prayers in the holy city of Karbala.
"They must avoid using excessive force with peaceful protesters."
He also warned against the exploitation of the unrest by "internal and external" forces which he said sought to destabilise Iraq for their own goals. He did not elaborate.
Protesters said security forces tore down tents at a sit-in in Karbala on Friday.