Authorities are investigating what they think was a home-invasion robbery that led to gunfire at an apartment complex in Alamitos Beach early Friday morning, according to Long Beach police.

Officers first headed to the apartment on East First Street between Falcon and Gaviota avenues around 4 a.m. after someone reported gunshots, Long Beach police department spokeswoman Arantxa Chavarria said.

When police got there, they found shell casings and other evidence that shots had been fired into and out of the apartment, police said.

Nobody was inside, but they found the apartment’s resident and another victim nearby, police said. Neither of them was hurt, according to Chavarria.

The robber or robbers stole an undisclosed amount of cash during the home invasion, LBPD spokesman Carlos Sandoval said.

It wasn’t clear who fired the shots or what touched off the shooting. Detectives were still investigating, police said.

Jeremiah Dobruck is managing editor of the Long Beach Post. Reach him at [email protected] or @jeremiahdobruck on Twitter.