Nearly 3.1 million travelers entered or exited Hong Kong during the Christmas holiday period starting from Tuesday, the special administrative region’s Immigration Department revealed on Thursday night.

Checkpoints logged over 946,000 cross-boundary travelers on Thursday, as of 9 pm, with about 522,000 arrivals and 424,000 departures, according to the authorities.

Among the cross-boundary travelers, over 104,000 were visitors and most of them entered the city via the West Kowloon Station – the city’s sole high-speed railway terminal — and the Hong Kong International Airport.

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The Lo Wu Control Point, a land port connecting to Shenzhen by the MTR East Rail Line, was the busiest checkpoint for outbound travel influx, the authorities said.

The city is expected to see 13.07 million cross-boundary passengers between Dec 21 and Jan 1.

To cope with predicted heavy traffic in checkpoints ahead of New Year, the Hong Kong SAR government will extend the service hours of the Lo Wu and Shenzhen Bay checkpoints on New Year’s Eve, increase the number of frontline officers, and open additional clearance counters and self-help channels to expedite cross-boundary passenger flows.

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Most of the city’s subway lines and light rail lines will operate overnight on Dec 31, MTR Corp has announced.

Li Qianxun contributed to the story.