Iraqi men chant slogans in Najaf as they carry the coffin of an anti-government protester, who was killed the day before during clashes with security forces guarding Baghdad's Green Zone, on Saturday, May 21, 2016. Haidar Hamdani/AFP/Getty Images

Protesters from Sadr City breached Baghdad's Green Zone for the second time in three weeks this weekend, demanding their government do more to curb corruption and protect citizens from Islamic State group militants. Four people were killed and more than 100 people were injured, some of them when police forces fired tear gas canisters and live ammunition into the crowd.

Protests have taken place in Baghdad over the last month as Prime Minister Haider al-Abadi attempts to appoint a new cabinet. The protesters are frustrated that the process to appoint a new cabinet of technocrats is slow. Although the demonstrations started peacefully, they quickly escalated when protesters scaled the Green Zone walls three weeks ago and culminated Saturday.

“The current political crisis threatens the stability of Iraq in an unprecedented manner, and the crisis could see the government collapse,” the Institute for the Study of War reported in a recent assessment of Iraq.

Abadi released a preliminary investigation Sunday that claimed police and military guards did not fire directly into the crowd of demonstrators, according to a statement released Sunday by Saad al-Hadithi, the prime minister's spokesman.

The protests are likely to continue as members of Parliament continue to stall on approving a new cabinet. Religious Shiite heavyweights are pressuring the Parliament to move faster, spurring more mass demonstrations.

In a handwritten letter last month, Muqtada al-Sadr, a powerful Iraqi Shiite cleric who used to support Abadi, called on the government to form a new cabinet . He warned that if the government did not move forward with negotiations, it could collapse altogether. Sadr warned that his supporters would attack ministries if demands for reform were not met. Earlier this month, his supporters stormed the Parliament building, forcing officials to flee.

The chaos in Baghdad is occurring while the police and security forces battle the Islamic State group, also known as ISIS, which still controls the major city of Mosul and much of western Iraq.

Abadi on Sunday announced the launch of the official campaign to oust the militants completely from Fallujah, a major ISIS hub in Anbar Province. The Iraqi security forces have for more than a year battled ISIS in Fallujah. They have failed to take over the city completely because they have been wary to shoot mortars into an area still occupied by civilians.

In an attempt to hold ground, ISIS has refused to let civilians leave the city. Thousands are stuck inside with limited water and food, officials say. U.S. military advisers are helping the Iraqis strategize in Fallujah and are training soldiers, specifically Sunni tribesmen from Anbar.

As the Iraqi security forces battle ISIS north of the capital, police in Baghdad are on the lookout for car bombs. ISIS has detonated several in the city over the last three weeks, killing hundreds of people.