The Manchester fire chief says four fires set overnight in the New Hampshire city were arson.
WMUR-TV says someone lit a mattress on fire was shortly after 1:00 a.m. Thursday on Manchester Street.
Then at about 2:45 a.m. someone set three trash can fires on Elm Street.
One of the Elm Street fires spread to a nearby building, which houses a bookstore. The damage to that building is said to be significant.
There were no injuries.
No arrests in the fires have been made.