U.S. Marines traded more gunfire with residents of Iraq's third-largest city Wednesday, marking the second straight day of violence in a place that may be a bellwether for the newly occupied country.

Hospital officials said a total of 17 people were killed and 18 wounded during civil disturbances over the two days. The U.S. Central Command said its troops were involved in a gunbattle Tuesday, but had no immediate comment on Wednesday's events.

Hospitals said 14 people died Tuesday, while U.S. officers put the death toll around seven. Three more Iraqis were reported fatally shot Wednesday and 17 wounded.

"They are killing us and no one's talking about it," Zahra Yassin said at a hospital with her wounded son. "We want Saddam back. At least there was security."

Twelve-year-old Omar Abdel Jabar said he was selling cakes when "the Americans started firing and I hid."

Wednesday's shooting apparently began with an attempt by police to drive looters away from the Central Bank, opposite the governor's office, which was the scene of Tuesday's bloodshed. The bank was in flames Wednesday evening and old Iraqi coins lay scattered in the street.

Wounded policeman Amar Ghanem Abdullah, 25, said he was among officers ordered to stop the looting. He said police fired warning shots in the air to disperse the crowd, and then U.S. Marines opened fire with a heavy machine gun on the roof of the governor's building.

"It was clear from where I was, where the sound was coming from," said Abdullah, who was wounded in both legs. The Americans "thought we were shooting at them ... We were just there to protect the people."

A Marine sergeant near the scene denied U.S. troops fired into the crowd.

The Marine, who would give only his first name, Chet, said that there had been gunfire from a building across a park from the Marines and that the Marines responded to that, rather than the police firing.

Mohammed Rabih Sheet, an administrator at Jumhuriya Hospital, said there were three dead at his hospital and 11 wounded, including two children. Dr. Ahmed Hikmat, a surgeon at Saddam Hospital, said six wounded were being treated there, including three in critical condition.

Six of the wounded at Jumhuriya Hospital who spoke to a reporter said Americans had shot them.

"I saw Americans standing on the street and on the roof shooting," said Mozafar Ahmad, 14, who was hit in the arm and above the knee. He said he was one of eight passengers injured on a bus driving by the governor's office.

In Doha, Qatar, the U.S. Central Command confirmed American troops killed some Iraqis during a riot Tuesday, but Brig. Gen. Vincent Brooks said the death toll was "on the order of seven."

He said U.S. forces defending the government compound fired only after being shot at and when some rioters in the street tried to climb over the wall.

Mosul has seen numerous disturbances since it fell without a fight Friday and Kurdish and U.S. forces moved in. Since then, tensions have escalated between Arab residents and the large Kurdish minority in the city of 700,000.

Iraqis said Tuesday's disturbance began when a large crowd turned violent in front of the governor's office during a speech by the new governor, Mashaan al-Juburi, a former journalist with the newspaper of Saddam Hussein's ruling Baath Party.

Al-Juburi assumed the governorship after the city fell, but has found opposition as well as support. He is an ally of Massoud Barzani, head of the Kurdish Democratic Party, which controls the western section of the Kurdish autonomous region.

Al-Juburi told the Los Angeles Times the crowd became enraged at the sight of a U.S. flag atop a building, an allegation denied by Lt. Col. Robert Waltemeyer, commander of the 10th Special Forces troops in Mosul.

The New York Times said the crowd of about 2,000 was angered by Al-Juburi's own words, which were pro-American.

In any case, Sathi Taha, a 32-year-old who was wounded Tuesday, told The Associated Press that people began yelling: "God is great!" and "There is no God but God!"

The mob began throwing stones at American troops, and overturned a car near the government compound's front entrance, Taha said.

Spanish newsman Miguel Rovira, who was at the scene from the start, told the Los Angeles Times that U.S. troops held their fire for about 20 minutes, but began shooting when the crowd tried to rush the building.

"They started firing at us," Taha told AP. "The crowd dispersed. Then the crowd returned ... then the Americans fired again. I ran. I crossed the street. I was hit in my leg, and when I was hit in my shoulder I fell on the ground."

At a Central Command briefing Wednesday, Brooks said U.S. forces were trying to secure the compound when the crowd began throwing rocks at Marines, hitting them with fists, spitting at them and setting cars on fire.

He said some of the Americans fired back after shots were fired at them and also shot at people in the crowd who tried to climb over the wall into the compound in a coordinated "assault."