Police are stepping up patrols in an area of Thetford after a series of fires.
The incidents happened at the Pines housing estate between 4:45am and 5:15am on Sunday (August 24).
Officers are also investigating a car fire which happened on Tuesday morning (August 26).
Suspects started a fire in the garden of a property on Elm Road which caused substantial damage to a shed and tree, and also spread to the garage of a neighbouring property.
Damage was caused to fence panels in the rear garden of an address in Elm Road after rubbish was set alight in an adjacent alleyway, and fence panels were also set alight in the garden of a house in Kimms Belt.
Shortly before 3am on Tuesday officers were called to Elm Road following reports of a car fire, after a Ford Focus had some form of liquid poured onto it and was set alight.
Breckland policing commander, Inspector Paul Wheatley, said officers would be carrying out additional patrols to provide reassurance to local residents.
He said: “These fires could have easily spread further, causing more damage and putting the lives of residents at risk.
“I would urge anyone who witnesses people acting suspiciously in this area to contact police on 101.”