The number of alleged gas explosions and fires in rock houses in a group of three cities north of Boston has increased to at least 70 with multiple reported injuries.
Massachusetts state police said Thursday's explosions rocked many neighborhoods and evacuations where there were gas odors.
Boston TV station WCVB-TV reports multiple injuries and said the local power company had disconnected electricity from affected communities. The city of Andover said in a statement that at least three people had been injured.
State police now calculate the number of fires and explosions in 70, compared to 39 initially reported, and the number is expected to grow.
There are no signs of foul play and local media reports suggest that the possible rupture of a gas line is to blame for WBZ News reporting that the first explosion was caused by an overpressured gas line.
Live television footage shows firefighters on the high stairs, battling flames engulfing low houses in Lawrence and North Andover, former industrial towns about 40 miles north of Boston.
The adjacent city of Andover was also involved.
The images published by the local media on Twitter showed numerous houses on fire or collapsed.
"We are asking everyone who has gas in their homes to leave their homes until further notice," North Andover village manager Andrew Maylor told a local television station.
The mayor of Lawrence, Dan Rivera, told WBZ: "What we know is that there have been multiple explosions, multiple fires that are happening throughout the city."
He said that residents who detect strange smells should leave their homes.
State police urged residents served by Columbia Gas, a unit of NiSource Inc, to evacuate their homes, saying the company was reducing pressure on their lines and that it would take "some time" to close all services.