Teen accused in series of knifepoint robberies in the Bronx

A teen is accused in a series of knifepoint robberies in the Bronx, police say. 
Police say the teen robbed four teenage victims during separate incidents between Oct. 10 and Oct 13.
The most recent incident happened Oct. 13, inside of St. James Park on E. 191st Street and Creston Avenue.
Police say the teen placed a knife to a 14-year-old girl's back and stole her cellphone before leaving on his bicycle.
He is described as being between 16 and 18 years old, 5'8'' tall and weighs 150 pounds.
Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.