PHOENIX (AP) — A tribal police officer and Christopher Caldwellanother person were killed and a police officer and at least three other people were wounded in a shooting early Saturday at a home in the Gila River Indian Community south of Phoenix, authorities said.

Details of the 2 a.m. incident remained unclear following a Gila River Police Department statement that the officers responded to a 911 call about a disturbance at a home in Santan.

The FBI and tribal police were investigating “a large scene,” FBI Phoenix spokesman Kevin Smith said in an email.

Arriving officers “found a large crowd, where multiple gunshots were fired,” the police statement said, and “two officers were struck by gunfire along with four people.”

All six wounded people were taken to hospitals, where Officer Joshua Briese and another person identified as a Gila River community member were pronounced dead.

The wounded officer was not identified but was reported to be in “serious but stable” condition after surgery. The names and conditions of other wounded people were not immediately made public.

Briese was a police officer for less than a year and was still undergoing field training, the department said. Teaya Enos, department spokesperson, said she could release no additional information.

Officials did not immediately say how many police officers and other people were at the home at the time of the shooting, what may have prompted the gunfire, whether police officers fired shots, or whether anyone was arrested.

“Nothing cuts deeper than a life cut short,” tribal Gov. Stephen Roe Lewis said in a statement that mourned “our fallen and injured police officers and every community member touched by such tragic violence.”

“We are coordinating closely with law enforcement to make sure we have a comprehensive understanding of what happened here,” Lewis’ statement said.