Police hunting for killer and murder weapon after midnight shooting

A gunman remains on the run after shooting a man in the chest at a unit block north of Brisbane overnight.

Neighbours heard a gunshot and a woman screaming that her boyfriend had been shot, at a complex on Young Street in the Moreton Bay suburb of Petrie just after midnight.

Emergency services found a 24-year-old with a serious gunshot wound to his chest.

He was treated at the scene and taken to Royal Brisbane and Women’s Hospital in a critical condition, where police have confirmed he died.

Forensic police remain at the scene today but have not found the murder weapon.

"Sometimes it takes us a little bit of time but we will find the person who is responsible for this and bring them to justice."

He said the absence of forced entry suggested the gunman was known to the victim but the nature of their relationship was not known.

Neighbours told 9NEWS there was a "massive bang".

"She ran straight up screaming, she was in hysterics... She was just screaming 'help me help me someone call an ambulance'," one neighbour said.

9NEWS understands two of the man’s friends witnessed the shooting and called Triple Zero. They are now speaking with police.

Police are not ruling out the possibility illicit drugs were involved. 

Anyone with information is urged to contact police. To make an anonymous report contact Crime Stoppers on 1800 333 000 or Policelink 131 444.