Eager fans swarmed Olympic ticket sales windows in Beijing on Friday, desperate to secure a pass to next month's main event.

A man gestures after purchasing tickets for next month's Olympic Games as they went on sale on Friday at a ticket booth in Beijing July 25, 2008. Thousands of people began queuing on Wednesday, in a last-ditch attempt to secure a ticket for the Olympics. [Agencies]

The final batch of 820,000 tickets, including 250,000 for events in the capital, went on sale at 9 am, much to the delight of the 30,000 people queuing outside a booth at the Bird's Nest, some of whom had been there for several days.

In the burning sun, patience waned and tempers frayed, and police had to cordon off several areas to maintain order. Hundreds of security guards lined the queues and Beitucheng Donglu, a major road in the area, was closed.

Felix Wong, a reporter from Hong Kong's South China Morning Post, was led away by police after breaking through a barricade and kicking an officer in the groin, the Xinhua News Agency quoted a Beijing municipal government information office spokesman as saying.

The reporter appologized for kicking the police officer, surnamed Zhang, who required hospital treatment, the spokesman said.

Things were noticeably calmer at the booth near the Wukesong Indoor Stadium in west Beijing, which will host the basketball competitions, where at least 10,000 people queued for tickets on Friday.

Every available ticket for the basketball - more than 20,000 - was snapped up on Friday, despite an original plan to sell them over three days, the organizers said.

BOCOG said on its ticket website that due to overwhelming response from the public, the number of tickets released on each day will be adjusted to meet the specific conditions at each booth.

It also reiterated that people are allowed to buy only two tickets each.