HAYFIELD — The Hayfield Fire Department is investigating the cause of a house fire that broke out in Waltham last Monday.

The fire, which caused minimal damage to the siding of the home at 98 Main St. E, started about 3:30 p.m. Monday. Fire fighters quickly extinguished the blaze, which stemmed from a burning pallet that was propped up against the house. After looking closer, firefighters found a green plastic bottle containing some foamable liquid underneath the pallet. Officials suspect somebody may have thrown the bottle at the house to start the fire. However, there are no suspects at this time.