Two people have been killed after flash flooding hit New Jersey and New York, as parts of the northeastern US braced for more harsh weather.

Torrential rain lashed the area on Monday night, with a flash flood warning issued for all five boroughs of New York City and a state of emergency declared in New Jersey.

Two people died in the state when their vehicle was swept into a river, with emergency responders at the scene unable to save them, local officials said.

Phil Murphy, the state’s governor, urged residents to “stay indoors and avoid unnecessary travel”.