Five explosions targeting local police shook the capital within the span of an hour Wednesday morning, two days after Iraq’s leaders requested that at least 5,000 U.S. military trainers remain into 2012 to advise the country’s fledgling security forces.

The bombs killed at least 22 people and injured more than 70, many of them police officers, in attacks across the city. It was the bloodiest day in Baghdad since Aug. 28, when a suicide bomber killed 28 people at the city’s largest Sunni mosque.

Car bombs rocked two police stations between 8 and 8:30 a.m. local time after two suicide bombers drove separate cars to the entrances of stations in Hurriyah, in northwest Baghdad, and Karrada, in the western part of downtown. Fourteen people were killed in Karrada and four in Hurriyah, according to the Interior Ministry. Sirens blared and Iraqi army helicopters circled as smoke plumed from the blast site in Karrada, the Associated Press reported.

Local police, whose capability and readiness have been questioned by U.S. and Iraqi officials, are constant targets for insurgents aiming to destabilize Iraq as the American military rapidly withdraws its forces.

In a meeting with Iraqi journalists Monday, President Jalal Talabani said Iraq’s political blocs have agreed that 5,000 or more U.S. military trainers are required to assist the country’s local and national security forces. Iraq will not, however, grant immunity from prosecution to military trainers who stay past the Dec. 31 expiration of the countries’ security agreements.

“The American side has been approached, and we are waiting for an official response,” Talabani said, according to the government-funded newspaper Assabah.

Both the U.S. military and the American Embassy declined Wednesday to comment on the number, though it is within the upper range of figures discussed in the past.

The radical Shiite cleric Moqtada al-Sadr, who has steadfastly opposed any American presence in Iraq, shifted his stance following Talabani’s announcement, indicating that he would support “indirect” training by the United States because it would mean fewer expenses and better weapons for Iraq. But such training, he said through a spokesman in Najaf, can take place only after the United States reimburses Iraq for damage caused during and after the 2003 invasion.

The United States and Iraq agree on the need for continued military training, though Defense Secretary Leon E. Panetta said last week that any remaining troops must have immunity. Since then, officials in Washington and Baghdad have rushed to outline training proposals that would enlist private security contractors, NATO or some other entity that could be legally covered despite the denial of military immunity.

 Earlier Wednesday, a sticky bomb detonated on the car of Brig. Gen. Ali Abboud as he was driving in the northern neighborhood of Selaikh, seriously injuring him. A bomb in a parked car exploded in the Ilam neighborhood in southern Baghdad as a police patrol passed a gathering of day laborers. Three civilians were killed.

At 8:45 a.m., another bomb in a parked car under Khattib Bridge in Hurriyah killed one person and injured 12. It was believed to have targeted a police brigadier general. At 9 a.m., security forces identified and disposed of an explosive charge near the main entrance to the Ministry of Interior in eastern Baghdad, after an officer on the nearby Muhammed al-Qasim Bridge noticed a man dropping off a suspicious plastic bag.

Car bombs, assassinations and collateral civilian deaths continue to be a daily occurrence in Iraq as U.S. troop numbers shrink from 41,500 service members and the State Department races to transform the mission into a diplomatic one using an estimated 16,000 civilians.

Majeed is a special correspondent. A special correspondent in Baghdad and special correspondent Saad Sarhan in Najaf contributed to this report.