Police are investigating three separate stabbings and slashings in Manhattan - all of which took place within a 24-hour span.

In the most recent incident, investigators say a man stabbed another man in the upper back around 5 p.m. Thursday on West 88th Street and Columbus Avenue on the Upper West Side. 

He made off with the man's Kindle and headphones.

A few hours earlier, police say there was a group of people waiting in a line outside the Supreme clothing store on Lafayette Street near Prince Street in SoHo, when a man cut the line and went inside.

They say when he came back out with merchandise, he was slashed in the face by another man.

And police continue to investigate after they say the teen seen here slashed the face of waiter at the Silver Spurs restaurant in Greenwich Village.

"It is alarming that they're slashing but overall given the amount of people in New York City, overall I feel safe," said one New Yorker.

"These things happen every now and then, hopefully they'll go away, the cops are doing a good job, we trust them," said another New Yorker.

All three victims were taken to nearby hospitals.

Meanwhile, former Police Commissioner Ray Kelly is speaking out about the slashings. 

During a visit to the New York Stock Exchange Thursday, NY1 spoke with Kelly, who said people have come to him expressing their concerns about their safety while walking around the city. 

"I think it's the random nature of a crime like this that really upsets people. You just don't have any ability to predict, have them on the subway, have them on the street so people are upset and concerned and it's understandable," Kelly said.

Kelly is also encouraging New Yorkers to stay alert and protect their belongings.