A 45-year-old man suffered a serious injury during a fight in Kalihi Tuesday morning when he was stabbed by “an unknown sharp edged object,” police said.

Police did not describe the injury that occurred during the “physical altercation” with a 31-year-old, male suspect. The incident occurred at 9:30 a.m.

Police have not made an arrest, but have opened a second-degree attempted murder investigation.

Detectives from the Honolulu Police Department’s Major Crimes Detail are handling the case.