Honolulu police opened a second-degree attempted murder investigation Friday night after a 21-year-old man was stabbed multiple times by four males during a robbery attempt in Waikiki.

According to a Honolulu Police Department report, at about 9:45 p.m., the victim was walking to his car when four males approached him and demanded his property. When the victim refused, police said, the suspects tackled him and stabbed multiple times.

The victim flagged down a vehicle and the motorist drove him to a hospital where the 21-year-old was admitted in serious but stable condition, police said.

The suspects are unknown, police said, and no descriptions were released. Police also did not release the exact location in Waikiki where the crime occurred.