Police arrested a man who they say was starting fires early Monday morning in Burlington.

Investigators say the call came in for a person throwing firebombs at about 12:30 a.m. on Park Street.

They say Henry Chalmers, 51, of Essex, started a fire in a recycling bin and one underneath an empty vehicle.

Chalmers pleaded not guilty in court on Monday.

Police say it's still unclear why he was setting off the devices that are similar to Molotov cocktails.

"What officers were able to find on scene appeared to be incendiary devices created out of jars with a small cap and a wick system to it," Burlington Police Lt. Jason Lawson said.

Chalmers faces two counts of second-degree arson and one count of recklessly endangering a person.

He has 10 prior misdemeanor charges and two felony charges.