Three people were killed and two were wounded in a shooting at an apartment complex in a Houston on Wednesday.

According to ABC 13, witnesses at Sunbury Downs Apartments said they heard gunshots ring out at about 4:30 p.m. local time before someone came running out of one of the complex’s units and left the property.

Five people in total were shot Wednesday afternoon and were shot multiple times each, including in the head, reports NBC News.

"I'd consider that an execution," Sheriff Adrian Garcia told the press Wednesday night during a statement.

Three of the victims were found already dead at the scene while two others, a man and a woman, were taken by helicopter to Memorial Hermann Texas Trauma Institute for treatment. Both of the living victims have been reported to be in critical condition.

All five of the victims are Hispanic and range in age from their late teens to their early 20s. None of their names have been released pending the notification of family members.

Authorities are not sure what caused the shooting. According to the Washington Post, there had been no signs of forced entry into the apartment and all of the victims were sitting when the gunman opened fire on them.

Garcia added in his statement that they found guns and illegal drugs in the apartment where the shooting occurred.

The gunman was still at large as of Wednesday night and has only been described as male.