The investigation began in late morning when the bodies of four people were discovered inside a home in the small town of Bowdoin, shortly before reports surfaced of several cars being fired on along Interstate-295 in Yarmouth, about 40km to the south, police said.

A search of a wooded area near the highway led to the arrest of one “person of interest,” state police officials said. Police said investigators had determined that the slayings of four people found in Bowdoin and the highway shootings “are connected,” but authorities declined to say how they were linked.

A stretch of I-295 near Yarmouth, about 6km north of Maine’s largest city, Portland, was shut down while police searched for a suspect. Authorities said there was no further threat to the public once they had detained the individual described only as a person of interest.

No further official details about the circumstances or motive behind the shootings in Bowdoin or Yarmouth was immediately available.

The four people fatally shot were not identified, and no information about their age or genders was released. Local media reported that one of the wounded motorists was listed in critical condition and one in serious condition. Police said at least one of the victims was undergoing surgery.