Over 30 cars have been torched since May 30. Most of the vehicles were in southwest Moscow.
A police spokesman told RIA Novosti that a car was set alight in southwest Moscow at around 1:00 a.m. Moscow time (21:00 GMT), close to where two vehicles were torched June 8.
According to witnesses a number of young people were seen in the area just prior to the fire.
A second car was set alight in southern Moscow around 5:00 a.m. Moscow time (04:00 GMT). Investigators are currently at the scene establishing the cause of the fire.
Moscow police earlier circulated a reward of up to a million rubles (about $42,000) for information leading to the arrest of the arsonist or arsonists. Several people were detained in connection with the fires on Friday, but later released. No one was charged.
