Investigations are under way after two parked cars in separate locations were destroyed by fire on Monday-Tuesday night.
The first blaze, at about 10.30pm, destroyed an Opel Astra parked in Triq Lapsi, Siġġiewi.
The second incident occurred in Triq in-Naħal, Qormi, where a Toyota Vitz was extensively damaged.
No one was injured, the police said.