An explosion and 2-alarm fire has been reported at New Brunswick's post office.

A fire following an explosion at the New Brunswick post office (@dclark0 via Instagram)

New Brunswick Police underground transformer exploded  shortly before 11 a.m. at the building on Bayard Street at Kirkpatrick Street.  The explosion caused flames to shoot out the front door.

Civic Square, City Hall, the Middlesex County complex and several buildings on Kirkpatrick Street were all evacuated. City Hall is open and operating normally; Civic Square's non-essential offices will stay closed until the transformer is repaired.

The post office was not open to the public at the time and four employees inside were evacuated.

Bayard Street is closed between George and Joyce Kilmer due to the explosion as is Kirkpatrick Street between New Street and Bayard Street.

The affected equipment has been de-energized by PSE+G. Their crews will put foam around the manhole where the explosion took place.

New Brunswick Municipal Court sessions scheduled for 12:30 p.m. and 4:45 p.m. on Monday have been canceled. New dates will be sent in the mail.