Harlingen (AP) -  Police say more arrests are possible in the stabbing death of a 14-year-old boy last week.

An 18-year-old Harlingen man was arrested on a murder charge. A police spokesman said Sunday that his name has not been released.

A police officer on patrol noticed a large disturbance Friday night, according to a news release.

"(The police officer) noticed a large group and what looked like a fight," police spokesman David Osborne told the Valley Morning Star. "As soon as he pulled up on the scene, everybody started running away."

The boy, who had a puncture wound in his abdomen, tried to stagger away but fell. He was taken to Valley Baptist Medical Center, where he died.

Two adults who had been stabbed were also treated at the hospital, officials said.

"An investigation was immediately under way after the incident, and based on witness statements, we were able to secure a murder warrant for the 18-year-old male," Osborne said. "He is now in police custody and is being charged with murder."

More arrests were still possible in what Osborne called "a very quickly developing case."