Police officers expressed their concern to Kathimerini yesterday about a resurgence in anarchist violence after seven arson attacks took place a few hours after two colleagues were attacked and disarmed by a group of youths. Five arson attacks took place in Athens in the space of two-and-half hours yesterday, starting at 2.15 a.m. in Vyronas when a homemade device containing gas canisters damaged a car belonging to the Church of Greece. At least 10 cars were destroyed after three car dealerships in Brahami, Alimos and Aghia Paraskevi were attacked. A minivan was also set on fire in Vyronas. Meanwhile, attacks with gas canisters on two branches of Eurobank in Thessaloniki led to their entrances being damaged. Nobody was injured in the attacks. The police, however, are worried that they are increasingly becoming targets for anarchists. On Wednesday, a patrol car was set alight during a march in central Athens. A day later, two officers on motorbikes were assailed by a gang of youths. A service revolver stolen from one of the officers was found yesterday in an empty apartment in Exarchia after a tip-off. Police sources said the officers had been monitoring the youths after they were seen putting up posters at the National Technical University.