Baghdad (AFP) - Iraqs cabinet endorsed a bill requiring a referendum be held on the Baghdad-Washington security accord that calls for American troops to leave Iraq by 2011, a government spokesman said Monday. If approved by parliament, the referendum will be held in January, on the same day as nationwide legislative elections, Ali al-Dabbagh said in a statement. The council of ministers approved (on Sunday) the holding of a referendum on the agreement between Iraq and the United States over the withdrawal of American troops, he said. Under the security accord, US troops were required to pull out of Iraqs urban centres by June 30, and must all leave the country by the end of 2011. If Iraqi voters were to reject the deal, the accord would automatically terminate in one year, meaning the deadline for US troops to withdraw from Iraq would be brought forward to January 2011. The January election will be the second since the 2003 US-led invasion that ousted slain dictator Saddam Hussein. The first was in December 2005. Meanwhile, at least eight people were killed, including two policemen, in three separate attacks on Monday in northern and central Iraq, police said. In the deadliest attack, five people were killed when a car bomb blew up near a convoy of US troops and Iraqi police near the town of Taji, just north of the capital Baghdad, local police Lieutenant Sarmed Sami told AFP. The bomb narrowly missed the joint patrol on a highway near Taji, tearing through a line of gridlocked cars, Sami said. He said 38 people were wounded in the attack. There were no casualties among Iraqi and US forces, he added. The US military did not immediately respond to a request for comment on the attack. In the restive northern city of Mosul armed men killed two policemen and wounded one civilian when they opened fire on a checkpoint in the centre of the city, a local police official told AFP, requesting anonymity. A drive-by shooting at a checkpoint in the town of Musayyib in the central province of Babil also killed one member of a Sunni Awakening, or Sahwa, militia group and wounded two, a policeman said. Despite a reduction in violence in recent months, attacks on security forces and civilians remain common in Baghdad, Mosul and in the ethnically divided northern oil city of Kirkuk. The number of violent deaths fell by a third last month to 275 from 437 in June, following the pullout of US forces from urban areas. The figure for May was 155, the lowest of any month since the US-led invasion of 2003.