All lanes of the Long Island Expressway were closed in both directions in Old Westbury Monday night due to an auto accident, Nassau County police said.

advertisement | advertise on newsday

The closure, which was announced at 11:15 p.m., affects all eastbound and westbound lanes between exits 39 and 40, according to an alert issued by police.

Nassau police described the accident as “serious,” but there was no other information about the crash immediately available Monday night.