BAGHDAD, July 16 (Xinhua) -- One United States soldier and three Iraqi children were wounded on Wednesday in a grenade attack in Baghdad, witnesses said.

　　An unknown attacker hurled a grenade at a U.S. armored vehicle stationed on the side of a highway in Baghdad's Mansur dis trict, causing a huge explosion, witnesses said.

　　The injured U.S. soldier was treated on the highway and later taken to hospital.

　　Three Iraqi children, who had been playing and chatting with the U.S. soldiers beside the armored vehicle, were also wounded in the blast, witnesses said.

　　The assailant had escaped the scene before other U.S. troops and Iraqi policemen arrived to seal off the area.

　　U.S.-led coalition forces have been under repeated attacks in recent weeks by what U.S. senior military officials believe to be die-hard loyalists of former Iraqi President Saddam Hussein.

　　More than 30 U.S. soldiers have been killed in hostile fire in Iraq since U.S. President George W. Bush declared the end of major fighting in the country on May 1. End