The car exploded in the center of the town of Hit, 140 kilometers (85 miles) west of Baghdad, shortly after a police patrol passed by, said Mohammed Fathi, a provincial spokesman. He said six children were also wounded in the blast.
The bombing came a day after the start of the new school year in Iraq.
Mohammed Abdul-Munim, the administrator of Hit who confirmed the casualties, said the initial investigations indicated the school was not the primary target of the attack but the police, most likely.
"Yet, once again, innocent people are paying the price for terrorist acts," said Abdul-Munim.
Violence has ebbed in Iraq, but insurgents still carry out frequent attacks on civilians and security forces in an attempt to shake the trust in the Shiite-led government.
