The Massachusetts Emergency Management Agency blamed the fires on gas lines that had become over-pressurized but said investigators were still examining what happened. It was not clear whether work was happening there Thursday, and a spokeswoman did not immediately comment.
Columbia Gas of MA, a NiSource company, in an update posted to its website at 11:10 a.m. Friday, said, "What happened in the Merrimack Valley.was a tragic incident".
Flames rise from a house after a series of gas explosions in the city.
Gas shutoff valves can be found on the pipe leading from the ground to your gas meter, or on the service line between the meter and the home. "We are focussed on providing as much support as possible to our customers, residents and communities", the utility said in a statement.
Live TV images showed firefighters battling blazes in the former mill towns of Lawrence, Andover and North Andover, about 25 miles (40 km) north of the MA capital.
The streets were darkened after nightfall with power cut off to the area as a precaution.
At least three people have been injured in Andover, including one firefighter and at least two civilians. Thirteen people were received at Lawrence General Hospital for injuries related to the explosions from smoke inhalation to blast trauma, according to the hospital's Facebook page.
Columbia Gas posted an online note shortly after the first explosions that read: "Crews are now responding to reports of multiple fires in Lawrence, MA". "This event is not over tonight. This event will probably go on. probably another week, a week and a half", he said.
Local media say a problem with a gas line that feeds homes in three communities north of Boston has caused the explosions.
Massachusetts State Police said around 70 fires, explosions or investigations of gas odour had been reported on Thursday, though by Friday afternoon officials said that all had been extinguished.
"It was very scary", she said.
It is believed the explosions were caused by gas leaks.
As Shafer was communicating with a Union Leader reporter, she said Massachusetts State Police told her and her parents they needed to evacuate the area.
Lawrence Mayor Dan Rivera said in a press conference that 12-14 homes were directly impacted, and while they can't located a geographic area, if you have gas in your home, you should evacuate.
In April, Columbia Gas filed a petition with the state's Department of Public Utilities to increase annual revenues by $24.1 million in part to help the company replace aging infrastructure.
That occurred when a Columbia Gas technician called to investigate a gas odor at a nightclub accidentally punctured a line, the state Department of Public Utilities said in a report.