The Travel Industry Council has cancelled about 200 bus tours to affected areas on the mainland because of safety concerns stemming from the severe winter weather.
About 6,000 people will be affected by the cancellations.
The tours, which were to depart from today to destinations including Huangshan, Jinggang mountain, Chenzhou and Shaoguan North, would have travelled on the Jingzhu Expressway - the most disrupted highway on the mainland.
Council executive director Joseph Tung Yiu-chung said more than 70 other mainland tours, affecting 1,200 people from Hong Kong, had also been cancelled. The industry has already lost more than HK$20 million.
Affected tour group members can either use their payments for other packages or seek a refund for a fee of between HK$150 and HK$300.
More cancellations could follow, the council warned. It estimates that, from tomorrow to February 12, the sixth day of the Lunar New Year, more than 1,000 tours - or between 30,000 and 40,000 people - will leave Hong Kong for affected mainland areas.