Online searches for flights from Hong Kong to Singapore surged 300% within three hours of the announcement an air travel bubble would open between the two financial hubs on Nov. 22, according to Trip.com.

Searches for Singapore to Hong Kong flights jumped 200%, and volume climbed for hotels in both cities as well, the online travel services provider said. “Hunger for cross-border travel remains strong,” it said in a statement.

Singapore Airlines Ltd. and Cathay Pacific Airways Ltd. will operate the air travel bubble flights, with both flying the route on the opening day and then operating three or four return flights a week until Dec. 7, from when they’ll both have a daily service. No more than 200 people are allowed on each flight.

The travel bubble agreement means any traveler from either place can visit without having to go through quarantine, which will be replaced by layers of testing. Singapore Transport Minister Ong Ye Kung said Wednesday that this is the first travel bubble of its type and may be used as a template for other countries, if successful.

The arrangement comes with a list of requirements and there is the possibility it could be halted for two weeks if the seven-day moving average in daily unlinked Covid-19 cases is more than five in either Singapore or Hong Kong.