BAGHDAD, Iraq (CNN) -- Insurgents launched a sophisticated and well-coordinated strike against police checkpoints in Baghdad on Wednesday that left five dead and at least 31 wounded, police said.

Thirty to 40 insurgents in civilian cars fired two rocket-propelled grenades targeting police patrols at a checkpoint, striking vehicles. Initially, police mistakenly thought a car bomb had been detonated.

Using RPGs, hand-held grenades, AK-47s and machine guns stashed in their vehicles, the insurgents attacked police at other checkpoints.

Among those killed were two police officers. Seven police were wounded.

Fighting between police and insurgents lasted about 90 minutes. Police said they killed at least one insurgent and wounded two others, who were arrested.

After the fighting, security forces went house to house looking for insurgents.

One of the injured insurgents was from nearby Amriya, where the insurgency has support, and the other was from Haifa Street, a stretch of Baghdad where anti-U.S. sentiment is popular.

The afternoon attack occurred in the Sunni Arab neighborhood of Jamiaa, near other insurgent strongholds, where violence has taken place in the past.

It differed from more surreptitious drive-by shootings, roadside bombings and car bombings that have become commonplace in the capital.

Earlier, Iraq's deputy minister of justice, Awshoo Ibrahim, escaped an assassination attempt in a western Baghdad neighborhood, police said.

Gunmen opened fire on his convoy along a major highway in the Adil neighborhood around 10 a.m. (2 a.m. ET).

Four of Ibrahim's bodyguards were killed in the attack and five others were wounded. Two vehicles were also destroyed.

On Tuesday, a suicide bombing killed seven people, including two Americans in Baquba.

A U.S. soldier from Task Force Liberty, a U.S. civilian contractor and five Iraqis -- four center employees and a police officer -- died in the strike on the Diyala Provincial Joint Coordination Center.

Among the wounded were nine Task Force Liberty soldiers, one U.S. civilian contractor, six Iraqi civilians and four Iraqi police officers.

The death brought the total of U.S. military killed in the war to 1,871 and the number of Americans killed in August to 73.