Police have opened a second-degree robbery and kidnapping case where a 21-year-old man said he was robbed while walking near the Lyon Arboretum gate in Manoa early Tuesday morning.

The victim told police that he was assaulted by two to three men at 12:30 a.m.

Police said the man was with a friend and was approached by a group of two or three males. They assaulted him took his personal items, police said.

The man’s friend was freed without harm.

University of Hawaii arboretum staff member found the man at 6:45 a.m. near the Lyon Arboretum gate at 3860 Manoa Road.

Paramedics took the victim to a hospital in serious condition, Department of Emergency Services spokeswoman said.