Prices of most domestic flights begin rising by up to 25 percent Tuesday, pushing prices for domestic tours for the May Day holiday up by about one third, the Daily Sunshine reported.

Airfares for group travelers for some routes will remain unchanged until May 10.

Air ticket offices in Shenzhen said most air routes would see a 10 percent rise in price and some would cost 25 percent more, the paper reported Monday (April 19th). A new State regulation allows airfares to be raised by up to 25 percent.

The more expensive flights are mainly tour flights and popular routes such as those to Beijing, Shanghai, Chengdu, Chongqing, Haikou, Xi'an and Kunming.

However, there may be discounts on some flights taking off early or late in the day.

A flight from Shenzhen to Beijing will rise from 1,600 yuan (US$193) to 1,750 yuan while it will cost 790 yuan to fly to Xiamen instead of 630 yuan. It will cost 1,400 yuan to fly to Shanghai, 130 yuan more.

Airlines did not offer any reason for the price hikes. But the newspaper cited sources as saying rising fuel prices, the holiday travel rush and the new regulation were reasons behind the airfare increases.

Travel agencies say the price hikes have affected the sales of tours by air. Most tours cost 10 to 30 percent more while some are even more expensive. Some tourists may turn to routes that are not so popular.

Editor: Catherine