Beijing - Thousands of people queued overnight for the opening sales Friday of the final 250,000 Olympic tickets available for events in Beijing during next month's Summer Games.

Local residents and many from outside Beijing flocked to the "Bird's Nest" National Stadium and other venues selling tickets with some people reportedly camping out since Wednesday evening.

Several hundred people were still queuing mid-morning outside one ticket office at the Worker's Stadium, which is to host Olympic football matches.

Another 570,000 tickets are on offer for football matches in the cities of Tianjin, Shanghai, Shenyang and Qinhuangdao, organizers said.

Yao Haiya, a 25-year-old woman from the southern city of Ningbo, told the official China Daily that she had bought a tent to camp out in the queue at the Bird's Nest since Wednesday.

"When I got here at 10 pm, there were already hundreds of people ahead of me," Yao told the newspaper.

Yao said she wanted to buy two tickets to see Liu Xiang, the 100-metre hurdles gold medallist in Athens, compete in the stadium.

"This is a once-in-a-lifetime chance to see the Olympics, and I can't afford to miss it," she was quoted as saying.

Tickets for popular Olympic events are reportedly changing hands for several times their face value.

The Beijing Times last week reported that one ticket for the opening ceremony with a face value of 5,000 yuan (730 dollars), was sold for 210,000 yuan.

About 7 million tickets have been sold for the August 8-24 Games, about 40 per cent of them in China. They were bringing in an expected 140 million dollars in revenue.

About 2 million more tickets were designated for the International Olympic Committee, sponsors, dignitaries and broadcasters.

Ticket prices for the events in 28 sports categories range from 30 yuan to 1,000 yuan.

To make the tickets affordable for ordinary Chinese, the price for 58 per cent of the seats was set at 100 yuan or lower.

Fourteen per cent of the tickets were reserved for students at a price of 10 yuan or less. (dpa)