A 4-alarm fire broke out at approximately 4:18 am at 135 Amherst Street in East Orange and quickly spread to three neighboring houses at 131, 137 and 139 Amherst Street.
East Orange city officials said the home where the fire started is believed to be vacant, but the other homes were occupied.
A total of 12 residents from three families have been displaced and are currently receiving assistance from Red Cross and CERT.
There were no injuries.
City officials said a total of 80 firefighters — all EOFD companies and mutual aid from Newark, Bloomfield, Montclair, and Orange — battled the blaze. South Essex, Millburn and Belleville covered East Orange firehouses.
The cause of the fire is still under investigation.