People hoping to take advantage of a Hong Kong scheme to give away half a million free airline tickets faced hours-long online queues on Wednesday, as the Asian financial hub bids to woo tourists back.

The city last month launched a campaign to reboot its reputation as "Asia's world city", after years of strict pandemic-related travel restrictions and a crackdown on sometimes violent pro-democracy protests.

On Wednesday, Hong Kong became one of the last places in the world to drop its outdoor mask mandate, which city leader John Lee said was a sign that it was "resuming normalcy".

Tourism once comprised nearly five percent of the city's economy, but visitor figures plunged last year to 600,000 -- less than one percent of 2018 levels.

Hong Kong-based carriers Cathay Pacific and Hong Kong Airlines were the first companies to launch the government-backed "Hello, Hong Kong" ticket giveaway, which will roll out over several months.

Social media users complained of long online queues to register, and an AFP reporter encountered wait times of more than two hours on the Cathay Pacific website. More than 55,000 users were waiting to access the offer, according to the reporter.

Cathay Pacific said its giveaway of 17,400 round-trip tickets from Thailand to Hong Kong had ended on Wednesday afternoon, despite initially being scheduled to last seven days.

The airline did not immediately respond to an AFP request for comment.

The first stage of the giveaway offered round-trip flights from Southeast Asia. Hong Kong residents will be eligible for a separate campaign for 80,000 tickets to be rolled out in July.

Hong Kong once had one of the globe's busiest and best-connected airports, but travel came to a virtual standstill when the city imposed strict travel restrictions and quarantine requirements as part of China's zero-Covid doctrine.

The restrictions helped the city remain largely virus-free, until a deadly Omicron outbreak at the start of 2022 that killed more than 9,000 people.

The city has now lifted most curbs, but, as of January, around 20 regional Asian airlines were unable to restart services to the city due to labour shortages