The first so-called drunk tanks have opened in Sydney as part of the New South Wales Government's crackdown on alcohol-related violence.

Police started operating the tanks in Sydney city and Randwick last night.

Assistant Commissioner Mark Murdoch says the centres are reserved for violent or nuisance drunks and well-behaved revellers have no need to worry.

"These are people who are intoxicated in a public place, have refused a move-on direction, are behaving in an anti-social [way] or are a danger to themselves or someone else," he said.

"If they fit that category, they're detained and taken into the sobering-up centre."

Five men aged from their late teens to their early twenties were the tank's first tenants, with each fined $200 on their release this morning.

The death of Thomas Kelly in July last year prompted the introduction of tough new conditions on some venues, including a ban on the sale of shots after midnight.

Kelly was king-hit while walking along the popular nightclub strip with his girlfriend and died in hospital two days later.

The State Government today announced further legislation to curb alcohol-related violence, including bans for disorderly behaviour, ID card scanners and greater supervision at high-risk venues.