A riot broke out at a Baghdad bank Thursday after thieves blew a hole in the vault and dropped children in to bring out fistfuls of cash. As ordinary Iraqis protested vehemently, U.S. troops calmed the situation by arresting the thieves and removing $4 million in U.S. dollars for safekeeping.

The incident — part of the lawlessness that has broken out in Baghdad with the fall of Saddam Hussein's regime — took place at a branch of the al-Rashid Bank. As word spread about the robbery under way, Iraqis gathered, demanding that the thieves give them the money. Many of them had accounts at the bank.

"These people want the money and they believe it is rightfully their money, but they don't understand that the proper distribution is not first-come, first-served," said U.S. Army Col. Philip DeCamp, a battalion commander.

Two men with Kalashnikov rifles shot over the heads of the crowd and ran for a nearby bridge. As the crowd grew larger and more agitated, a U.S. special operations patrol called in reinforcements, and an Army platoon arrived.

The patrol arrested a dozen men inside the building, several of them teenagers. As the soldiers brought out the thieves, the crowd cheered, chanting, "Good, good, mister!" while the parents of the teenagers wept and begged the soldiers to release them.

About 1,000 civilians surged around the 16 soldiers attempting to secure the bank building. At one point the soldiers cocked their rifles and charged at a group of men to get them to back away from their Bradley fighting vehicles.

One special operations officer found a resident who spoke English and had him use a loudspeaker to calm the crowd and ask them to move away from the troops. After the troops spread concertina wire around the bank entrance, most of the Iraqis wandered away.

DeCamp ordered that a hole in the vault be enlarged and that the U.S. and Iraqi currency be removed and taken to his base for safekeeping.

Troops blew open the vault with C-4 explosives, finding about $4 million in $100 bills, sequentially numbered in Federal Reserve wrappers and stacked in bricks of $10,000 each. Soldiers put the money in burlap bags and took it away.

Banks — and black markets — were the focus of anti-looting efforts all around Baghdad on Thursday.

Marines patrolling a rough Baghdad neighborhood where currency is exchanged on the black market traded fire with suspected looters, killing one, U.S. officials said. Five or six others were arrested. The shooting took place in the al-Kifah section of southern Baghdad.

Marines also removed bags of money for safekeeping from another burned-out al-Rashid branch that has been hit repeatedly by looters in the al-Shorga neighborhood.

U.S. forces have begun to crack down on lawlessness in the Iraqi capital amid criticism that they have not done enough to protect the city. Troops have been patrolling night and day to quell the disorder.

"The looting goes down every day, and I think you will continue to see it go down because the Iraqis are now stepping up and controlling the problems for themselves," said Gen. Tommy Franks, commander of U.S. forces in Iraq.

He said 2,200 Iraqi civilians volunteered in the capital Wednesday to work as unarmed police officers — a step that could relieve the pressure on U.S. troops to try to establish order.

About 300 Iraqi police were on the streets Thursday, working with U.S. Marines. Together they have arrested 400 looters and other offenders, U.S. Marine public affairs officer Staff Sgt. Jose Guillen said.

In addition, imams in the predominantly Shiite Saddam City neighborhood were detaining looters on their own.

American forces were also distributing 5,000 cellular phones to key police and firefighters in Baghdad to speed communications in emergency situations.

In other positive signs, looted vaccines and other medical supplies were returned Thursday to the headquarters of the Red Crescent. And at the Baghdad police academy, newly recovered stolen cars were parked, and people lined up to claim their vehicles.

U.S. forces expect to get one of Baghdad's power grids online by Friday afternoon, restoring some electricity to residents. As of Thursday, Guillen said, six diesel plants were operating and have restored power to 500 homes.

Fifteen hospitals were now open in the capital and the United States just delivered 17 tons of medical supplies to the city, he said.