Nearly 25,000 people in the New Jersey towns of Carteret and Port Reading were warned Friday morning to boil their water after a large water main break.

"ATTENTION ALL CARTERET RESIDENTS! Due to a large main break early this morning on Longfellow Street a Boil Water Advisory is in effect for ALL Carteret residents until further notice," Middlesex Water Co. tweeted just before 8 a.m.

The water utility later added that Port Reading residents east of the New Jersey Turnpike would have to boil their water as well.

It was not immediately clear how long they would be without service.