Macau authorities reinstated tough COVID-19 curbs including locking down a major casino over the weekend after a handful of cases were detected, even as China announced a loosening of visa rules for visitors to the world's biggest gambling hub.

Authorities locked down the MGM Cotai casino resort owned by MGM China on Sunday, with staff and guests ordered to stay inside until Nov. 1. All of Macau's 700,000 residents are mandated to take rapid antigen tests daily during the period, the government said.

The prospects for travel to Macau have improved, however, with China's immigration bureau saying on Monday that mainland residents would be able to use an online visa system from Nov. 1 to travel to Macau.

There are still multiple COVID-19 testing requirements to enter Macau and to return to the mainland but the resumption "greatly alleviates the frictions for a Macau trip ... and could signal to many that 'it's OK' to come to Macau now."