Iraqi protesters occupied part of a main bridge in Baghdad on Saturday that security forces had pushed them away from a week before, a Reuters photographer said.
Demonstrators also occupied a tall building overlooking the bridge, taking new ground in the centre of the Iraqi capital after protests had appeared to lose momentum.
A bomb blast at a nearby square during the night killed at least three people, police and medics said, but it was not immediately clear who was responsible or whether it was linked to demonstrations.
More than 300 people have been killed during weeks of mass unrest in Baghdad and southern Iraq.
Protests that began in October over lack of jobs and public services have swelled. Demonstrators are now demanding the departure of Iraq's ruling class and an overhaul of the governance system that has fuelled corruption since the toppling of Saddam Hussein in a U.S.-led invasion in 2003.
Security forces have used live ammunition, tear gas and stun grenades against mostly unarmed demonstrators, killing an average of nearly 50 people a week since Oct. 1, according to a Reuters count based on police and medical sources.
More than a dozen members of the security forces have died.
Prime Minister Adel Abdul Mahdi's government has warned against any violent protest. It is under pressure from powerful religious authorities to ensure violence does not escalate and to enact real reform to improve the lives of Iraqis.
Shia-majority Iraq has suffered decades of war, sanctions and sectarian strife, most recently the brutal rule of Sunni Muslim extremist Islamic State over vast swathes of the north from 2014 to 2017.
But despite a rare period of calm since IS was defeat, many people in the region's second-largest oil producing country suffer poverty, unemployment and poor healthcare. They accuse lawmakers and senior officials of pocketing public money and doling out jobs and wealth to their own kin or parties.
Demonstrators also decry what they see as foreign interference in the running of the country, including from the United States but especially from Iran whose allies have dominated Iraqi state institutions since 2003.
Iraq closed a southern border crossing with Iran to travellers on Saturday over unrest in both countries, a security official said.