A 19-year-old man who had asked two men for a cigarette in Waikiki Saturday allegedly assaulted one of the men and demanded money from the other, police said.

The man was arrested for investigation of first-degree robbery and third-degree assault with a deadly weapon.

The 18- and 21-year-old victims were walking in Waikiki around 3:20 a.m. when the 19-year-old man approached them and asked for a cigarette, police said.

When the 18 year old denied the request, the 19-year-old man accused the victim of calling him a name and then assaulted the 18-year-old man, police said. 

The two victims were walking away when the suspect allegedly used an unidentified weapon and demanded money from the 21-year-old man, police said. 

A witness flagged down a police officer and the suspect was later arrested.