Dozens of fires and explosions broke out on Thursday afternoon in Lawrence, Andover and North Andover, and the state police advised all residents of those communities that receive their gas service from Columbia Gas to evacuate their homes immediately.
"Gas pipes are currently depressurized by the company," but it will take "a while," the state police said in a tweet.
Firefighters were called to 39 addresses in Lawrence, Andover and North Andover to receive reports of suspected gas fires and explosions, and this number is expected to continue to grow, according to the state police.
"In places where gas was smelt, there are a lot of evacuations going on, and" there are soldiers on site to help with scene security and traffic control, "the state police said.
The state police said it was "too early to speculate about the cause" and a "joint investigation will be conducted when the situation stabilizes".
Local TV helicopter footage showed clouds of smoke and orange flames rising from several buildings in the area.
A spokeswoman for the state fire department said that there was a first report of a gas pipeline overpressure that caused fires and explosions. Investigators from the office are on their way to the area.
The Massachusetts Emergency Management Agency said its employees are on their way to helping "with multiple fires and possible overpressure in the gas pipeline."
"The state fire mobilization plan has been activated for 4 structural fire crews for mutual assistance from other parts of the state," tweeted the agency.
Governor Charlie Baker "is actively monitoring the situation in the Merrimack Valley and communicates with first responders and public security officials, and urges residents to follow local officials' instructions for key public safety announcements, including evacuation and suspension of gas use," the spokeswoman for the organization said Governor, Lizzy Guyton.
A gas service is offered in the Columbia Gas area. A spokeswoman for Columbia Gas did not immediately return a phone and e-mail requesting a comment.
The Columbia Gas Web site said in a post on Thursday, "We will upgrade natural gas pipelines in neighborhoods across the state." The site says there are four projects underway in Lawrence, four in Andover, and three in North Andover.
The Columbia Gas website says it has about 50,000 customers in the Merrimack service area, including Lawrence, Andover, North Andover, as well as Methuen and parts of Haverhill.
"National Grid", which powers the region, is also responding to household power cuts, said Christine Milligan, spokeswoman for National Grid.
In the north of Andover, Garry Frizzell, 50, said he smelled gas in his house at 4:45 pm.
"I said," I started the stove "- then I realized that I had not used it in three days," he said in front of his house and several emergency vehicles roared at two nearby fires.
Nearby, on the main street, heavy smoke came from the upper window of a house as several firefighters tried to put out a fire. Neighbors gathered to see and exchange what little information they had.
A man ran from house to house and switched off gas pipes.
"It's like Armageddon," Frizzell said later as he walked away from a fire that had been crushed to another. "I was in the bombings of the Boston Marathon and that–" "He pointed to the smoke, the fire engines, the helicopters that swirled overhead -" reminds me. "
Jordan Burgess Sr., 80, another neighbor near the fire on Main Street, smelled gas and left his house.
"The police chief, he was right in the street, saying," Do not go back to the house, "Burgess said.
North Andover Town Manager Andrew Mayor tweeted that there were "several bonfires" in the city.
"If you smell gas, do not go home, you can evacuate to North Andover High School," he said. "As a precaution, the city now advises all residents with natural gas to evacuate their apartments until further notice."
Merrimack College in North Andover ordered all students, faculty and staff to clear campus buildings immediately.
Lawrence Mayor Dan Rivera could not be reached by the Globe for comment. But in an interview with WBZ-TV, Rivera urged residents of South Lawrence to evacuate their homes.
"If you're at home in South Lawrence and smell gas, clear your house. If you see fire in and around your house, "evacuate," Rivera said.
"If you smell anything like gas, take no chances," Rivera said.
Lawrence police, EMS fire and the Red Cross were on site.
Rivera would not say if there were any injuries.
"We try to put it together," he said.
Methuen police chief Joseph Solomon said that Lawrence burned 20 to 25 homes. Solomon, who is in Lawrence, says there are so many fires, "you can not even see the sky."
The city of Andover said on Facebook that residents should turn off their gas if they know how to make it safe.
"ATTENTION ANDOVER: If you know how to shut down your gas safely, please do so, residents and businesses are advised to evacuate, and we will post updates as soon as we have information," the statement says.
The fires affected transport in the area. Off-ramps off Interstate 495 from junction 42 to exit 45 have been closed. The ramps remained open to allow evacuation. Service on the Haverhill commuter line was also interrupted.
Katherine McCabe from Globe staff contributed to this report. Material from The Associated Press was used in this report.