Stricter liquor laws have helped to cut down rowdy incidents in neighbourhoods, though minimarts have suffered reduced takings of at least 5 per cent.

Some convenience stores that previously closed at around midnight are now shuttering earlier because they are no longer allowed to sell alcohol - a big source of income for some - after 10.30pm, said Mr Alan Tay, the chairman of the Singapore Mini Mart Association.

New laws since April 1 prohibit the retail sale of alcohol and drinking in public places after 10.30pm.

In Little India and Geylang, the rules are more stringent and retailers are not allowed to sell alcohol from 7pm on weekends, public holidays and the eve of public holidays.

JS Minimart in Jurong West used to close at around 11 to 11.30pm but now shuts at about 10.30pm.

Said its owner, Mr Rafiqul, 38: "People used to buy alcohol right up until we closed. Previously, we could make up to $350 a day from alcohol alone - now it's only about $200 to $250... Sometimes, it is difficult to cover rental."

Minimarts that are open 24 hours might see an even more drastic drop in sales, added Mr Tay.

The bright side is that littering and disturbances caused by drinking have become less frequent.

Mr Rafiqul, who lives in Jurong West, said: "Before the new rules, some people would buy alcohol and go to a nearby playground or void deck to drink. Sometimes, there would be shouting and it would go on till very late into the night."

Coffee shop workers have also noticed changes. Said Madam Lim Siew Choo, 67, who runs a drink stall: "Before the new laws, once or twice a week we would have to call the police because drunkards would be making trouble, sometimes fighting. I would also arrive at work to see lots of litter left by them. We no longer have any trouble in the mornings."