(CNN) -- Two Los Angeles Police Department officers were injured in a brazen ambush outside a police station Tuesday morning.
The two veteran detectives were using their key card to enter the Los Angeles Wilshire police station when someone came up from behind and opened fire, LAPD Commander Andy Smith said.
One officer suffered a head injury, either from a bullet that grazed him or a chunk of debris, Smith said. A bullet grazed the second officer's hand, he said.
Both officers were treated and released from a hospital.
The shooter is still at large, Smith said.
The officers work on an undercover burglary task force, but it is unknown if the attack was related to their assignment.
"Usually, burglars don't go after the people that are searching for them, so this seems like a more violent suspect," Smith said.
Such a brazen attack outside a police station is very unusual, he said.
All of the LAPD's 19 police stations increased their security as a precaution, he said.