The attack happened around 5:02 p.m. on a Bx2 bus near East 163rd Street and the Grand Concourse, according to authorities.
Police say the victim was taken to NYC Health + Hospitals/Lincoln and is expected to survive.
Investigators are searching for a suspect described as a man in his 30s, wearing all black. He fled northbound on foot along the Grand Concourse.
The investigation remains ongoing.
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