Police have opened a second-degree attempted murder investigation after a 25-year-old man was apparently stabbed during an early-morning altercation in Waikiki.

According to police, the man was engaged in a physical confrontation with another man around 5 a.m. Afterward, as both men were walking away in different directions, the victim realized he had been stabbed and alerted an acquaintance, who called 911.

A city ambulance crew located the victim from a parking lot near Kuhio Avenue and Lewers Street and transported him to an area hospital in serious condition.

No arrest has yet been made.