NEW YORK  — Three children died after being found on a New York City beach early Monday and police believe they may have been drowned by their mother.

The 7-year-old boy, a 4-year-old girl and a 3-month-old girl were found on Brooklyn’s Coney Island beach shortly after 4:30 a.m. and taken to a nearby hospital, Chief of Department Kenneth Corey said. All three were pronounced dead there.

The children’s 30-year-old mother had been picked up earlier about 2 miles (3.2 kilometers) away, Corey said. She was being questioned at the local stationhouse.

Police first got a call at about 1:40 a.m. from a concerned relative of the mother who “indicated she was concerned that her family member may have harmed her three small children,” Corey said at a news conference near where the children were found.

Officers went to the woman’s apartment building in the Coney Island neighborhood, where a man identified as the father of one of the children said he was similarly concerned.

Officers canvassed the area and found the woman about 90 minutes later, barefoot and soaking wet. She was still being questioned by detectives later Monday morning. “So far, she’s not said anything,” Corey said.

The search intensified and police located the three children on the beach. Efforts to revive them failed, Corey said.