Russian President Vladimir Putin on Sunday urged leaders of the 12-member club of ex-Soviet states, some of them already shifting to the West, to stick together to fight extremism and terrorism. Putin, avoiding controversy as he raised the curtain on three days of summits and parties marking the Allied victory over Nazi Germany, made no mention of the political about-face in four members of the Commonwealth of Independent States, Reuters said. But, referring to a U.N. call to fight national extremism, terrorism, racism and xenophobia, he said: "I am convinced the CIS is capable of becoming an effective instrument for such a joint fight." Security forces threw a ring of steel around Red Square and the Kremlin -- focal points for celebrations on Monday that will be attended by U.S. President George W. Bush and more than 50 other world leaders. The biggest danger comes from Chechen separatists who have staged deadly attacks throughout Putin's five years in power and rarely let Victory Day pass without incident. Russia seeks help from CIS neighbours in efforts to cut their supply routes and end a campaign seen by many here as a threat to Russian unity. Ten of the 12 leaders attended the informal summit of the CIS, an ill-assorted alliance of states stretching from Central Asia on the border with China to the edge of the European Union. It was an occasion for Putin to reflect on Russia's waning influence, in a region where it once held absolute sway, as former colonies shift their allegiance from Moscow and towards a welcoming and more financially alluring West.