Relatives of the victims of the Beslan school siege gathered Sunday to pay tribute at the ruins of the school, remembering the 330 people, including 186 children, who lost their lives in Russia’s deadliest terror attack. School bells rang at 9:15 a.m. local time, marking the start of the siege 20 years ago, while mourners laid flowers, lit candles, and placed bottles of water — a tribute to the hostages who were held in inhumane conditions. On Sept. 1, 2004, militants from Chechnya stormed Beslan School No. 1 in North Ossetia, demanding the withdrawal of Russian forces from Chechnya. Gunmen to…