A majority of outbound tour groups are opting to travel by high-speed rail to spend the Christmas break this year on the mainland, the Travel Industry Council said on Wednesday.

Speaking on RTHK, executive director Fanny Yeung said the number of tour groups heading out of Hong Kong during this holiday break, 1,500, was of a similar level to that of a year ago.

The most popular options for holidaymakers are a three- to four-day tour of places like Guilin and Chaoshan.

"During every major festival, like Christmas and Easter, many of our tour groups travel by high-speed rail because it costs the same all year round and there is no fuel surcharge or air passenger departure tax," Yeung said.

The number of tour groups flying off to many places in Southeast Asia, she pointed out, has dropped by 20 percent, except for Vietnam.

Vietnam is an exception because of promotional efforts for destinations such as Da Nang and Phu Quoc, Yeung added.

As for inbound travellers, she said, overseas visitors have exceeded the number of mainlanders as Christmas is not a public holiday across the border.

Some 4,000 tour groups from the mainland will make it to the SAR this month, she said, about 2,000 fewer than in November due to rises in accommodation fees during the festive period.

Meanwhile, travellers also flocked to the airport to spend the holidays elsewhere.

One man said his family joined a five-day tour to Xi'an for some HK$8,000 per person.

"It's a little expensive compared to non-peak travel season. We normally spend Christmas in Hong Kong with our friends," he told reporters.

"This time, we felt the chance to go on a family trip doesn't come often, so we picked these few days."

Another man said his family was heading to Vietnam.

"We haven't really planned our itinerary in Da Nang. We will just have good food, enjoy the nature," he said.

A woman, meanwhile, said her family opted for a tour to Shanghai and Suzhou as they plan to spend around HK$5,000 each.