Iraqi security forces clashed with anti-government demonstrators in Baghdad on Sunday with at least 39 people, most of them police officers, injured by projectiles unleashed from each side, security officials said.
Police sources said tear gas canisters being fired by security forces had injured at least seven people.
A separate statement from a military spokesman said at least 32 members of the security forces were injured by hand grenades thrown by a group he suggested had hidden among otherwise peaceful protesters, without elaborating.
Politicians have expressed concern at the possibility of peaceful protests being hijacked by rioters, which could set off a spiral of violence such as that witnessed last year.
Renewed anti-government rallies converged on Sunday to mark a year since mass unrest over corruption and widespread deprivation in oil-rich Iraq. More than 500 people have been killed in the disturbances.
Protesters marched in the capital and several southern cities, including Najaf, Nasiriyah and Basra.
Earlier in the day, police fired water cannon and tear gas at protesters in Baghdad to prevent them crossing barricades on a bridge leading towards government buildings.
Security forces had deployed in force to control protests that began in the morning, and to stop demonstrators crossing Joumhouriya bridge, which leads to the fortified Green Zone that houses government buildings and foreign missions.
The renewed protests are a test for Prime Minister Mustafa al-Kadhimi, just five months in power. Al-Kadhimi has been vocal about his support for the protester's demands.
