(CNN) -- One Chandler, Arizona, police officer was killed and two others were wounded during an investigation in south Phoenix home Wednesday night, a police spokesman said.
"It was an undercover operation," said Steve Martos with the Phoenix Police Department. "Beyond that, I don't have any further details."
One or two suspects were also killed when gunfire broke out, according to Martos, who said two other suspects also were shot and are hospitalized, and two others have been detained.
CNN's Nick Valencia contributed to this report.