Baghdad ? A suicide bomber tried to kill Iraq’s labor minister Thursday, slamming an explosives-laden sport-utility vehicle into an official convoy and killing nine people, authorities said. The minister, Mahmoud al-Sheikh Radhi, was not harmed.

The blast occurred in what is regarded as one of the safest areas of the Iraqi capital, just 200 yards from the entrance to the heavily guarded Green Zone, which includes the U.S. Embassy and the offices of Iraq’s prime minister.

Violence in Iraq has decreased sharply in the past year. In a sign of progress, U.S. officials on Thursday handed over control of security in Babil province, just south of Baghdad, to Iraqi authorities. Babil is the 12th of Iraq’s 18 provinces where Iraqi authorities are now in charge of security. The province includes most of what was once known as the “Triangle of Death” because of the danger it posed to U.S. soldiers.

The U.S. military still hasn’t turned over security responsibilities in Baghdad, which has been plagued by deadly explosions.