Tensions in the run-up to the Moscow mayoral election mounted this week as police raided four supporters of leading opposition candidate Alexei Navalny in a five-hour operation, sawing through a steel door and confiscating two tons of allegedly illegal campaign leaflets. One of the four members of the grassroots group, “Navalny’s Brothers,” was taken into custody for 10 days, and three others got away with 1,000 ruble fines ($30) Wednesday on charges of disobeying a police order. The group recorded the raid and broadcast it live online. The crackdown was launched overnight on a complaint by rival candidate Nikolai Levichev, who said he had received a tip that campaign leaflets were being produced illegally in a rented apartment near downtown Moscow’s Chistoprudny Boulevard. Confusion reigned about whether the officers – who had no search warrant – had the right to be in the apartment. Police said during the raid that they thought the apartment was on fire, which in Russia is a valid pretext for trespassing without legal authorization, but an officer later claimed in court that the apartment’s owner had allowed them to enter.