LEWISTON — Two downtown men were arrested Friday night and charged in the Monday-morning blaze that destroyed two buildings and damaged a third.

Bryan Wood, 23, of 131 Bartlett St. and transient Brian Morin, 29, were each charged with three counts of arson. Police said both men are known to the department and each has a criminal record.

Morin, a convicted sex offender, went on television news earlier in the week and insisted he had nothing to do with the latest fire. Morin has been living with Wood in recent days, police said. He was first questioned about the fire early Monday.

The Monday-morning blaze destroyed two vacant buildings on Bartlett Street and damaged a third apartment building on Horton Street. Police don’t believe the fire was related to a pair of similar fires the week before.

At a Friday night news conference, Lewiston police Chief Michael Bussiere described an intense investigation that included several local, state and federal agencies. Maine Drug Enforcement agents have been working their sources all week, as have agents from the Central Maine Violent Crimes Task Force.

Lewiston police and the State Fire Marshal’s Office were assisted by the Bureau of Alcohol, Tobacco, Firearms and Explosives.

“We have some people who will blow your doors off when they’re looking for someone,” said Fire Marshal Joseph Thomas. “It’s quite an operation.”

Bussiere said the teams of investigators have been working pretty much around the clock — “all hands on deck,” the chief said — since the first fire rattled the city. With the capture of Morin and Wood Friday night, each of the three fires has resulted in arrests. A pair of 12-year-olds were arrested in the earlier blazes.

“It’s been very difficult,” Bussiere said. “There have been a lot of expectations within the community. “As a result of these arrests, hopefully people can sleep a little easier tonight.”

The chief said extra patrols would remain on the streets in hopes of preventing further chaos. In addition, city officials have secured roughly 20 vacant buildings since the fire investigations got under way.

The number of abandoned tenements reminds Thomas of Portland in the 1970s, when a series of fires swept through the city.

“It’s cyclical,” he said. “It’s Lewiston’s time. They have a lot of vacant buildings and they’re easy targets.”

Police did not discuss any possible motive Wood and Morin might have had for starting the fire. Although the MDEA was involved in the investigation, there wasn’t necessarily a drug connection.

“They have their connections,” Thomas said. “They know what’s going on.”

Wood has a criminal history of assault, reckless conduct and other charges. In early April, he was arrested  by Lewiston police on charges of obstructing government administration, refusing to submit to arrest or detention and violating a condition of release.

In 2002, Morin was convicted of unlawful sexual contact.

The blaze Monday night was started in the early morning, police said, while most tenants were sleeping. Firefighters responded after the 2:46 a.m. call and arrived to find the backs of three buildings — 114 Bartlett, 118 Bartlett and 91 Horton — in flames.

After they were arrested at about 7:30 p.m., Wood and Morin were taken to the Androscoggin County Jail in Auburn where they were being held without bail Friday night.

More coverage of the Lewiston fires:

• How to help
• Timeline of events
• Map of downtown fires
• Aerial view of downtown