A suicide car bomb exploded at a checkpoint at the main entrance of Baghdad's Green Zone on Tuesday, killing two Iraqi policemen and wounding one, police said. The high-security area is home to Iraq's parliament and the U.S. Embassy, the Associated Press reported. The explosion, which sent plumes of black smoke up over the Green Zone, occurred at about 1:20 p.m. at the gate that many Iraqi employees use to enter and leave the area where they work for Iraq's government or for the U.S. and British embassies. The powerful blast killed two Iraqi policemen and wounded another one, said police Lt. Mohammed Kheyon.