HOUSTON - Three people were fatally shot and two others were injured at an apartment complex in the US city of Houston Wednesday afternoon, local media reported.

The shooting happened shortly before 5 pm (GMT 23:00) at a complex in northwest Houston, local media KHOU reported. Two women and one man were already dead by the time authorities arrived at the scene. Another man and woman were transported via LifeFlight to a medical center. Their conditions are not known.

According to the Harris County Sheriff's Office, witnesses said a man shot the victims inside the apartment, closed the door and fled. Officials said all five victims were shot in the head.

Police have launched a manhunt to track down the gunman. The motive of the shooting remained unknown. The identities of the victims have not been released.