NEWARK, N.J. — Fire crews are battling a blaze that has damaged at least seven buildings on a residential block in New Jersey’s largest city.

Authorities say the fire broke out shortly before 1:30 p.m. Wednesday in an abandoned building at South 20th and Ferdinand streets, about two miles west of the downtown area.

Hot weather and low water pressure hampered the firefighting effort.

Two buildings have burned to the ground, and five nearby homes have been damaged.

Fire department spokesman John Brown said about a dozen firefighters, working in 90-degree temperatures, have been treated for heat-related injuries.

There are no reports of injuries among residents.

Fire officials have not determined the cause.