BAGHDAD     -     At least six more Iraqi protesters were killed Saturday in clashes with security forces in Baghdad and the southern town of Nasiriyah, as thousands took part in nationwide anti-government protests, officials said.

Thousands of protesters were trying to reach Baghdad’s heavily fortified Green Zone, home to embassies and government offices. Security forces fired tear gas as protesters tried to remove blast walls from a main bridge leading to the government district. Three people were killed when they were struck by tear gas canisters, security and medical officials said.

A second medical official said three protesters were shot dead by security guards when they attacked the office of a provincial official in the southern town of Nasiriyah. The town in the mainly Shiite south has seen especially violent protests in recent weeks and was placed under a 24-hour curfew on Friday.

At least 48 people have been killed since the protests resumed this week, after 149 were killed in a wave of demonstrations earlier this month. The spontaneous, leaderless protests are directed at the political establishment that came to power after the 2003 US-led invasion, which many blame for spiraling corruption and poor public services.

The Interior Ministry and the military issued statements Saturday saying some protesters have exploited the rallies to attack government buildings and political party offices. The protests against the Shiite-dominated government have been largely concentrated in Shiite-majority areas.

The ministry said some of its members were killed as police battled violent protesters but did not give a number. The military warned that it would take necessary and legal measures to deal with those it called saboteurs.

Iraqi officials said 12 of those killed Friday died in a fire they had set when they stormed the office of a government-backed militia in the southern town of Diwaniyah. A security official said protesters torched the offices of at least three militias in southern Maysan province.

All officials spoke on condition of anonymity because they were not authorized to talk to reporters. In Baghdad, Iraqi police had fired tear gas, rubber bullets and live shots on Friday to break up protesters who gathered in the central Tahrir Square and later tried to cross the bridge leading to the Green Zone. The protesters returned in Saturday, clashing with security forces throughout the day.

The rallies have mainly been by young, unemployed men who are demanding jobs and better services. Young women appeared among the crowd in Baghdad for the first time Saturday, some handing out water to the protesters.

Some protesters had set up tents in Tahrir Square. Mukhaled Fares, 19, sat on the ground barefoot, carrying a backpack with the Iraqi flag over it. He said his family has migrated to Germany but he refuses to leave Iraq.

“I want change. I want to remove those corrupt people who sleep in the Green Zone and who fired tear gas and rubber bullets at us,” Fares said.

A widow who identified herself as Um Layth, or the mother of Layth, said she had asked her son and daughter to stay home because she feared for their safety. But the 60-year-old from outside of Baghdad said she came to protest, wanting a better future for her children. Her husband died in Iraq’s eight-year war with Iran in the 1980s.

“I am not afraid if I die, but I want a better future for my children,” she said. “If these parties and this government stay, they will have no future.”

Iran emerged as a major power broker in Iraq after the 2003 invasion and has close ties to many of its most powerful political parties. Iran also backs a number of state-sanctioned militias that were mobilized in 2014 to battle the Islamic State group. “Iraq is free. Iran out, out!” some protesters chanted in Tahrir Square.