Officers arrested a 29-year-old Palolo man following an assault that injured a 22-year-old man in the Nimitz area, Honolulu police said.

The suspect struck the victim on the head with a “dangerous instrument” causing “substantial bodily injury,” at about 10 a.m. Friday, police said.

Officers arrested the suspect at 10:55 a.m. at the main police station on suspicion of second-degree assault.

Police did not give an exact location of the incident. They also did not say what kind of weapon was used and did not release a condition on the victim.