Detectives from the Hawaii Police Department are investigating an assault that reportedly occurred early Thursday morning at a bar in downtown Hilo.

At about 12:01 a.m., South Hilo patrol officers responded to the drinking establishment after receiving the report of a man having been assaulted by another man.

Sometime between 11:55 p.m. and midnight Wednesday, an unidentified man made contact with the 27-year-old Hilo victim in the restroom of the bar and struck him on the face. The suspect fled the area on foot. He was last seen heading in the makai direction on Haili Street and then southbound on Kamehameha Avenue.

The victim was initially treated at Hilo Medical Center. He was later sent by air ambulance to The Queens Medical Center on Oahu, where he was listed in critical condition.

The suspect is described as a man in his 20s, approximately 5-foot-6, about 185 pounds with short black hair. He was wearing a light-colored shirt and dark-colored shorts.

Police ask anyone with information about the case to call Detective Regino Saludares at 961-2379 or the Police Department's non-emergency line at 935-3311.

Tipsters who prefer to remain anonymous may call Crime Stoppers at 961-8300 in Hilo or 329-8181 in Kona. All Crime Stoppers information is kept confidential.