At least 354 have been killed since antigovernment protests began at the start of October and more than 8,000 have been wounded, the United Nations High Commission for Human Rights said. Its most recent report notes “the actual total is likely to be higher.”

Many of those killed, like one boy, Hussein Abid, 16, who was shot Thursday near Al Ahrar bridge in Baghdad, look even younger than their age; they are largely unarmed and come from poor families. He came from Sadr City, a vast Shiite slum in eastern Baghdad.

The protests and accompanying violence have occurred almost entirely in Baghdad and the Shiite south of Iraq, where mostly young people and poorer people have taken to the streets demanding sweeping changes in the political system. They want to see an end to the political parties, which demand kickbacks for licenses, contracts and jobs.

Even young people applying for low-level positions like security guards or elementary schoolteachers who are not affiliated with the correct party might be asked to pay $5,000 for a state job, a large sum for most Iraqis. In Iraq, government positions are viewed as the only secure jobs and the private sector remains small.

Many of the parties that dominate Parliament are close to Iran and it is an open secret that Iranian officials helped to set up the current government last year, brokering an agreement that brought in Mr. Mahdi, President Barham Salih and the house speaker, Mohammed Al-Halbousi.