NEPTUNE, N.J. (AP)  -- A small, four-seat plane crashed Saturday night in shallow waters off Monmouth County, but authorities said it was not immediately clear whether anyone was killed or injured.

Coast Guard Petty Officer Nyx Cangemi said the plane went down at about 6:50 p.m., about a quarter-mile from the Shark River Municipal Marina in Neptune. The wreckage was entirely submerged, and rescue workers said the aircraft's fuselage was buried deep in the riverbed mud.

It was not immediately known how many people were aboard the plane, which crashed near Shark River Island in about three feet of water, Cangemi said.

Witnesses, though, said they did not see anyone pulled from the wreckage.

A Coast Guard Station rescue boat responded to the scene, along with several local agencies, and the rescue operation was ongoing as of about 9 p.m.

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