A 19-year-old unarmed man was fatally wounded by Long Beach cops after they believed he was pointing a gun, officials said Friday.

Hector Morejon of Long Beach was shot an unknown number of times Thursday afternoon and taken to a local hospital, where he was pronounced dead, according to the Long Beach Police Department.

Police said officers received a report that several people were trespassing and vandalizing a vacant apartment in the 1100 block of Hoffman Avenue.

When they arrived, they found an open window in the back of the apartment and a broken window.

An officer peered into the apartment and saw a man standing against a wall, then turning toward him, police said.

The man bent his knees and extended his arm “as if pointing an object which the officer perceived was a gun,” police said.

“At this point, an officer-involved shooting occurred,” police said.

No weapons were found at the scene and the Long Beach spokesman did not identify the shooter.

Officers said the apartment was spray-painted with gang-related graffiti.

They arrested Long Beach residents Edgar Rodarte, 20; German Rodarte, 21; Yesenia Pineda, 22, and Celia Cox, 22, on suspicion of trespassing. German Rodarte was held on suspicion of also violating a gang injunction, police said.

Police didn’t respond to requests for information about the number of times Morejon was shot and whether he was holding an object.

Long Beach police said they are investigating the fatal shooting. The Los Angeles County district attorney’s office is conducting a separate, independent investigation, which is customary in all officer-involved shootings.