London:
London's Olympic transport system faced a major test on Friday as thousands headed for the Olympic Park for one of the busiest days of the games so far as track and field events kicked off at the main stadium.
Organisers say more than 200-thousand people are set to visit the Olympic Park on Friday and the platforms at nearby Stratford Station were packed with commuters during the early morning rush.
Severe delays were reported on several routes to the park on Friday.
Transport for London reported that the underground's Central Line, which links the centre of the city with the Olympic complex, had been briefly suspended because of a signal failure.
Officials said full service was resumed by 9 am (0800 GMT) after a partial suspension that lasted more than an hour, but there were still delays in the line mid-morning.
The delays have a knock-on effect throughout the system as commuters and Olympics fans switch to other lines.
Officials were also restricting access to an oversize shopping mall next to the Olympic Park on Friday and Saturday because of the large crowds expected.
Only ticket holders or accredited workers will be allowed into the mall during the day.
Meanwhile inside the venue streams of excited ticket holders marched across Olympic Park, filling its concourses.
The athletics events at the London Olympics finally kicked off Friday after a week of competition.
For many of the lucky ticket holders the athletics promises to be the highlight of the games.
"It's unpredictable. It's like power, speed, strength it's everything put together in the perfect athlete. It's brilliant," said Maree Harris from Devon in the United Kingdom.
It will also give many spectators a first look at the setup of 80-thousand seat Olympic Stadium and of course the Olympic cauldron which has been hidden away in the, until now, empty stadium.
"We've seen it on TV but we haven't seen it yet so we're really excited," Debra Lebe from London, who was accompanied by her 13-year-old daughter Anna.