A water main break has prompted school officials to a two-hour delay to the start of the school day for students at Watchung Hills Regional High School and Green Brook Township on Friday.

According to Warren Township police, the water main break is located behind the high school, in the area of Mountain Avenue and Regional Drive. Police say Mountain Avenue will remain closed until further notice, as crews work to repair the break.

Students and staff have made their way back into the high school as classes began at 9:30 this morning.

Before Care in Green Brook started at 9 a.m.

Officials say the break happened sometime overnight.

Police are urging drivers in the area to plan alternate routes as the repair work continues.