A 4-year-old boy waiting for a bus with his uncle was groped by a stranger Friday in an incident that incensed witnesses, Hempstead police said.

People at the bus terminal on West Columbia Street forcibly restrained the suspect, holding him until police arrived, authorities said.

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Police said the man grabbed the boy’s genitals when his uncle was chatting with someone at about 2 p.m., police said.

The child did not require medical care. The suspect, who was beaten by people in the crowd, was taken to a hospital before being charged, police said.

The Nassau police special victims unit has taken over the case.

Other details, including the suspect’s name, were not immediately available.