ANTWERP, BELGIUM (AFP) - Frustrated Dutch tourists have flocked to neighbouring Belgium to escape a tough Covid-19 lockdown over the festive period, despite appeals from the authorities not to head across the border.

The Netherlands has imposed the tightest winter restrictions in Europe by closing down non-essential shops, restaurants, bars, cinemas, museums and theatres until Jan 14 in a bid to curb infections fuelled by the Omicron variant.

But just next-door, Belgium has so far opted for lighter measures despite fears the new strain could spark another wave of infections in the country.

Dutch visitors were out and about in the city of Antwerp on Thursday shopping and stopping in at bars and cafés that are shuttered back home.

"We just wanted to escape the lockdown. Everything is closed, actually, we have nothing to do, and it's our holiday," Dutch tourist Charleigh said, declining to give her surname.

"So we thought it was more fun to come to Belgium."

Local businesses said that the lockdown in the Netherlands was helping provide a much-needed boon after tough times during the pandemic.

"In the past few days, most of my clients are Dutch," said ice-cream vendor Marie.

"So it's very good for our business."

The influx of visitors comes despite warnings from the Dutch health minister and even its railway service not to head across the border.

"We do not recommend travelling to Belgium by train for the next few days, unless it is really necessary," the Dutch national train service tweeted on Wednesday.

"Due to large crowds, keeping sufficient distance is impossible. We have extra staff on the platforms and will continue to monitor the situation in the coming days."

Belgium's Belga news agency reported that around 7,600 Dutch visitors travelled by train to Antwerp on Wednesday and that there were jams on the roads.

The large numbers prompted the city to bolster police deployments on Thursday to ensure visitor safety and regulate traffic.