WARWICK, R.I. (AP) — Officials have ruled that arson is to blame for fires that heavily damaged two cottages overnight in Warwick's Oakland Beach neighborhood.

Michael Sweeney, chief of investigations for the state fire marshal, says investigators determined the fires early Monday were intentionally set, although he said it was too early to tell what caused the fires.

The first fire was reported around 1 a.m. Monday. The second was spotted just as firefighters had gotten that one under control.

The cottages are not far from one another. Both are seasonal and were unoccupied at the time. No injuries were reported.

Officials are offering a reward of $5,000 for information leading to a conviction.