Russian gamblers are placing their final bets before casinos close down for good in Moscow and other big cities. A new law that comes into effect Wednesday says gambling must now be confined to four far-flung special zones. Casinos and slot machines will now be allowed to operate only in Kaliningrad on the Baltic Sea, the Primorsky region on the Pacific coast, the Altai region in Siberia and near the southern cities of Krasnodar and Rostov. Casinos proliferated in Russia's cities after the 1991 collapse of the Soviet Union, and slot machines quickly spread beyond gaming halls to shops and malls. The spread of gambling has provoked distaste among many Russians over the flashy cars parked outside glittering casinos in Russia's capital and the harm that gambling can do to society. "Let them close," said Galina Beleznikova, 65, a retiree who has seen friends lose their homes and their families because of gambling addictions. "For that matter, get them out of Russia altogether." Although the law was signed in 2006 during Vladimir Putin's presidency, many casino owners did not expect the closures to actually come into effect. Critics say the move will merely push gaming underground, leaving 400,000 people without legal jobs amid the country's economic crisis. Putin is now prime minister. Several prominent casinos on Moscow's glitzy Novy Arbat street have closed down ahead of the deadline. Others plan to remain open until the last possible moment before closing their doors for good. Some casinos may reinvent themselves as private poker halls - a much less lucrative business than roulette and blackjack. The law on poker remains ambiguous, however, and some casino owners say they will not take the risk. Police have vowed to check establishments across Russia the minute the law comes into force on July 1 to ensure compliance.