A suicide bomber driving a tractor near Iraq's Abu Ghraib prison has blown himself up in the second attack on the facility in the past two days.

Police say at least four civilians were hurt in Monday's blast.

The U.S. military says Saturday's assault on the prison involved multiple, simultaneous attacks. It estimates the assailants suffered 50 casualties, and says 23 U.S. troops and 13 detainees were wounded.

Meanwhile, Iraqi Shi'ite and Kurdish negotiators seeking agreement on the makeup of a new government are meeting today, before parliament's next session Wednesday. Lawmakers say they hope to select a new president, two vice presidents and a prime minister when the session convenes.

Sunday, lawmakers elected a Sunni Arab cabinet minister, Hajim al-Hassani, to head the new assembly.