HOUSTON -- A police officer shot at two men who threatened him with what turned out to be toy gun near downtown Houston early Monday, officials told KPRC Local 2.

Houston police said officers working security were alerted to a robbery in a parking lot near the Invasor nightclub on Line Street near Hardy Street at about 1:30 a.m.

Investigators said one of the men pointed what appeared to be a gun at an officer.

"It's a plastic toy gun almost identical to a Glock model pistol," Detective Kevin Rivera said.

The officer fired several shots at the men, police said.

"Whenever a suspect raises a weapon toward an officer, it's that officer's duty to protect himself and citizens in the area," Rivera said.

The men dropped the toy gun and ran away, officials said.

Detectives said they do not know if the officer's gunfire struck either man.

The toy was collected as evidence and the officer and a witness were taken in for questioning.

"Early in our investigation, our opinion is everything seems to be forthright," Rivera said.