ST. LOUIS- Two federal marshals and a police officer were wounded Tuesday in a gunfight with a suspect who died following a standoff at a St. Louis home, authorities said.

One marshal is in critical condition, a hospital spokeswoman said.

St. Louis police confirmed in a statement that a "male suspect is deceased." The brief statement did not explain who the man was or how he was killed.

Talking to reporters outside the house, Sannita Vaughan said her brother was the dead suspect who had been holed up inside.

"All we know is, they killed him," Vaughan said as relatives tried to shield her from the media crush.

The two U.S. marshals and a police officer had been serving an arrest warrant at the house on the city's south side when a gunfight broke out, according to Jeff Carter, a spokesman for the U.S. Marshals Service.

One U.S. marshal is in critical condition in the Intensive Care Unit at Saint Louis University Hospital, spokeswoman Laura Keller said. The other is in fair condition and is undergoing surgery, Keller said.

She did not provide the officers' identities.

A St. Louis police officer was hit in his bullet-proof vest and suffered a graze wound and injuries from a fall, according to a recorded statement on the city police media hotline. It said he was taken to the Barnes-Jewish Hospital.

Jason Merrill, a spokesman for the Barnes-Jewish Hospital, confirmed that one person wounded in the shooting was being treated there, but provided no name or details of that person's condition.

Earlier Tuesday, city police spokeswoman Schron Jackson said police were involved in a standoff at the property, but she had no more information.

Police cordoned off several blocks on every side of the house with police tape in the neighborhood in a poorer section of the city's south side. They blocked access to the property with police cars and vans.

Television video footage from KTVI in St. Louis showed one marshal being carried down an alley by several officers and being put into an ambulance.

There has been no word on any arrests.

Earlier Tuesday, Vaughan told reporters that her brother was inside the house and had been shot by police. She looked into television cameras and implored the brother to come out and surrender.

As police began to disband, bystanders appeared inflamed and began shouting obscenities at police. One officer with a police dog tried to quell the tempers.

--- Associated Press writers Margaret Stafford in Kansas City, Kan. and Christopher Leonard in St. Louis contributed to this report.

(Copyright 2011 by The Associated Press. All Rights Reserved.)