BRATISLAVA (Reuters) - Some 20,000 Slovaks gathered on Bratislava's main square on Monday to commemorate the Velvet Revolution which eight years ago ended 40 years of communist rule in the former Czechoslovakia. The crowd jangled their keys -- a gesture frequently seen during anti-communist protests in 1989 -- on Slovak National Uprising square which saw the biggest demonstrations against the then government. The meeting in Bratislava, which became the capital of independent Slovakia after Czechoslovakia split in 1993, was organised by the opposition Slovak Democratic Coalition (SDK). It was one of eight similar rallies in Slovak towns, but there was no immediate indication how many people attended these. Officials of the ruling coalition of three nationalist and populist parties did not speak on Monday, leaving the field open for the opposition to repeat its accusations that the government has betrayed the ideas of the 1989 revolution. "Those people who are in power at present have stolen November (1989) and we have to take it back," said Ján Čarnogurský, currently a leader of the opposition Christian Democratic Movement (KDH), who spent some time in prisons before 1989 for anti-communist dissident activities. The opposition also accused the government of delaying Slovakia's integration with the West. Slovakia was once considered to be among top candidates for early membership in the European Union (EU). But the country's chances have deteriorated in the past few years as the EU has repeatedly criticised Bratislava for falling behind in implementing democratic reforms.