Two venues breached NSW’s new lock-out laws on the first Friday night they took effect.

One of Friday’s breaches included patrons going back inside a pub to fetch clothing they left behind earlier in the night.

While police say it is too early to call the tougher trading restrictions a success, NSW police Assistant Commissioner Mark Murdoch said there was less violence and aggression on the streets.

“Less drunks on the street … far fewer drunken people on the street, less aggro, less violence, better behaviour,” he told reporters on Saturday.

“It’s far too early to claim success but if what we saw last night is any indication we are heading in the right direction.”

An additional 50 police were deployed across Sydney’s entertainment precinct on Friday night as licensed premises implemented the 1.30am lock-out and 3am last drinks, which came into effect on Monday.

The precinct includes Kings Cross, the CBD, Cockle Bay and The Rocks.

Mr Murdoch said police also issued 10 temporary ban notices and applied for one long-term ban order from the party precinct.

The long-term ban stemmed from an alleged assault inside a club on Bayswater Road, Kings Cross.

Mr Murdoch said one pub on King Street in the CBD breached the 1.30am lock-out.

“Significantly that breach of the lock-out we say will attract a strike offence,” he said.

Another premises in the CBD also breached the lock-out when the venue let a couple of people back inside to collect clothing.

Paul Newson of the Office of Liquor Gaming and Racing said it served as a reminder of what the lock-out means.

“Lock-out means from 1.30am, no entry and no re-entry of patrons.”

The penalties for breaching the trading restrictions range from an $11,000 fine or 12 months in jail.

Mr Newson said that overall, venues were well-prepared and there were high levels of compliance.

With thousands of people expected to flock to Sydney on Saturday night for Mardi Gras, police will face another test of the new laws.

“Tonight is probably not a true indication to us of the new measures,” Mr Murdoch said.

“We are going to see hundreds of thousands of people come into the city to attend Mardi Gras that would not normally be there.”

Oxford Street is the traditional drawcard for Mardi Gras party-goers, with a string of venues with 24-hour trading.

Those venues will still have to stop selling alcohol at 3am but it will only be two hours before their trading kicks in at 5am.

Mr Murdoch said police saw very large numbers in some venues on Oxford St on Friday, including around Taylor Square, where venues traded beyond 3am.

“It has shown that people can and venues can continue to trade and stay in those venues and … enjoy themselves without the alcohol,” he said.