China's tourism sector is seeing another booking frenzy ahead of the five-day May Day holiday, with long-haul domestic trips and outbound tours being particularly sought by visitors, industry players said.

The number of flyers is expected to reach a new high during the holiday period from May 1 to May 5.

Economy-class flight tickets on several popular routes are sold out and only business-class tickets are still available, said Beijing-based travel agency Qunar.

The average price of a domestic flight ticket during the holiday was 990 yuan ($136.6), slightly higher than the rates recorded in the same period last year and about 60 percent more than the offseason price in March, according to Qunar.

"Demand for travel during the May Day holiday this year has been strong, and there are insufficient flight tickets on some routes. We suggest that passengers wishing to travel purchase their flight tickets as soon as possible," said Xiao Peng, a researcher with the big data research institute of Qunar.

The travel peak is expected to commence as early as Saturday, as some workers may take three days off, from April 28 to 30, to extend that into an eight-day-long holiday period.

Bookings of packaged tourism products such as group tours, self-driving tours and cruise voyages have been climbing, said Tuniu, a Nanjing, Jiangsu province-based online travel agency.

Shanghai; Beijing; Sanya, Hainan province; Nanjing, Jiangsu province; and Guangzhou, Guangdong province are among the popular tourist destinations.

Other cities with a unique cultural charm, trendy style, seaside scenery and distinctive cuisine have also attracted bookings from many young travelers, Tuniu said.

"Japan, the Maldives, Thailand, Singapore, Indonesia and New Zealand have witnessed robust bookings. Some European countries such as Spain, Portugal, Germany, France and Switzerland are also hot picks by Chinese travelers," said Qi Chunguang, vice-president of Tuniu.

The search volumes for flight tickets have also increased significantly.

For instance, on April 16, the search volume surged 130 percent over the level of April 15, according to VariFlight, an aviation data and solution services provider.

Tokyo, Osaka, Seoul, and Singapore are hot outbound tour destinations as far as flight searches go.

Japan saw the highest search volumes. With the depreciation of the Japanese yen, it is forecast that Japan as a tourist destination will become even more popular, Vari-Flight said.

As of April 16, the number of passenger flights connecting China and Japan had recovered to more than 70 percent of the level seen during the pre-COVID period of 2019.

The number of flights connecting China and Singapore has approached close to the 2019 level, VariFlight found.