HONG KONG (Reuters) -Casino revenues in Macau, the world's biggest gambling hub, surged 366% from a year ago to total 15.6 billion patacas ($1.93 billion) in May, the highest since January 2020, when the COVID-19 pandemic had still to fully grip China.

The monthly take was bolstered by a five-day national holiday that saw hundreds of thousands of visitors flock to the special Chinese administrative region, which is the only place in China where citizens can legally gamble in casinos.

China lifted strict COVID-19 restrictions in January, allowing visitors to swarm into Macau for the first time in more than three years.

Around 500,000 people visited the former Portugues colony during the five day Labour Day holiday at the start of May, crowding onto its pastel coloured streets surrounding historical sights Senado Square and the Ruins of St Paul's and packing its glitzy casinos.

Authorities are keen to diversify sources of income in Macau, which depends on casinos for more than 80% of its government revenues, and have imposed strict new regulations on its six casino operators.

The rush of visitors comes as the densely populated territory grapples with an acute labour shortage, a key concern for casino operators Sands China (OTC:SCHYY), Wynn Macau (OTC:WYNMF), MGM China (OTC:MCHVY), SJM Holdings (OTC:SJMHF), Galaxy Entertainment and Melco Resorts.

Sands last week officially opened its "Londoner" casino resort which includes a 6,000 seat arena and attractions like a replica of London's Big Ben clock tower.

It was the first big casino opening since the COVID pandemic and was attended by former England football captain David Beckham who drew scores of fans to the property.

($1 = 8.0840 patacas)