BAGHDAD, March 20 —Insurgents detonated a bomb in a car carrying two children after using the children as decoys to get through a military checkpoint in Baghdad, an American general said Tuesday.

Speaking at a news briefing at the Pentagon, Maj. Gen. Michael D. Barbero, deputy director for regional operations at the Pentagon’s Joint Staff, said that American soldiers had stopped the car at the checkpoint but allowed it to pass after they seeing the two children in the back seat.

“Children in the back seat lower suspicion,” he said, according to a transcript. “We let it move through. They parked the vehicle. The adults run out and detonate it with the children in back.”

General Barbero offered no further specifics about the incident.

Lt. Col. Christopher Garver, a top American military spokesman in Baghdad, said late Tuesday that his office had no record of the bombing but was researching it. “I don’t know what event he’s talking about,” Colonel Garver said, Agence France-Presse, quoting an unnamed American military official, said the incident occurred Sunday. The bombers parked the vehicle across the street from a school and then ran away, leaving the children inside, the official told A.F.P. The blast killed the two children and three other civilians and wounded seven, the official said.