Fortress Smith: Arkansas police said that three people were killed after an officer fired his gun while defending himself from a knife attack.
The police provided little information about what had happened, including how people died and what caused police officers Fort Smith to fire his gun.
The police did not immediately say whether there were people who died shot by officers or whether they might be stabbed.
The incident occurred around 6:15 AMSUNDAY at Fort Smith, located around 160 miles (260 km) northwest of Little Rock.
The officer was injured and underwent surgery on Sunday morning, Aric Mitchell, spokesman for the Smith fortress police department, said.
The department asked Arkansas state police to investigate.
Bill Sadler, Arkansas State Police spokesman, said he could not immediately provide additional information.
Mitchell and Sadler said the authorities could provide more information on Sunday afternoon.