By Mark Simpson BBC Ireland correspondent

On-street drinking at the weekends is the curse of many town centres. But in Ballymena, County Antrim, it's being successfully tackled - thanks to a tactic borrowed from the football pitch.

Yellow cards warn of tough penalties

Picture the scene - it's just after midnight and you're walking home from the pub with a bottle of beer in your hand, when a police officer stops you, reaches into his top pocket and brandishes a yellow card.

It may sound like something from a TV sit-com, but in Ballymena this is really happening.

And it's the police who are having the last laugh, because the scheme is proving to be a major success.

The aim of the campaign is to stamp out on-street drinking.

Before the scheme began some pubs gave drinkers plastic glasses and allowed them to stand drinking on the pavement.

This created an intimidating atmosphere in the town centre and with more people on the streets, there were more fights.

Ballymena developed a reputation as an unsafe place for a night out.

The initiative, called Operation Socialise, is changing that.

The local council is involved, as are many of the pub and club owners in the town.

Cards are handed out to pub customers

Throughout the summer, anyone caught drinking on the street has been issued with a yellow card.

This softly-softly approach is, however, about to stop.

From mid-September, on-street drinkers will be faced with prosecution - and a fine of up to �500.

In recent weeks, some local people have had more yellow cards than Roy Keane could expect to get in a lifetime.

Police say the message is getting through.

Inspector Kevin Hayes says the amount of on-street drinking has been dramatically reduced - and Ballymena itself is reaping the benefit.

"More people are coming back to the town centre and that's something that we want to encourage.

Chief Insp Kevin Hayes: Want town to be safe

"We want to have a thriving night-life - but we want people of all age groups to feel safe," he said.

Town centre manager Colin Neill agrees. "Ballymena is a cool place to socialise. Operation Socialise is to make sure it stays that way."

In the past year, the level of violent assault in Ballymena has been reduced by 80%.

The owner of Whispers restaurant and nightclub, Nigel Cobb, says: "You couldn't get better for Ballymena.

"Since the yellow card scheme started off - and we used the radio link with the police - my business has grown at least 50%."

Like every other town, Ballymena has its problems. It has more than its fair share of is sectarianism, theft and drug-dealing.

The difference now is that the problems with alcohol are less likely to spill over onto the streets.