North Korea's Olympic representative Ung Chang expressed outrage on Thursday at a diplomatic blunder which resulted in his country's women's soccer team leaving the field after the South Korean flag was displayed by mistake.

"Of course the people are angry," International Olympic Committee (IOC) member Chang said.

"If your athlete got a gold medal and put the flag probably of some other country, what happens?"

The match against Colombia at Glasgow's Hampden Park on the first day of sporting action at the London Olympics on Wednesday, two days before the opening ceremony in the British capital, was delayed by more than an hour.

North and South Korea have been bitter enemies since their 1950-53 war. They have also been drawn against each other in the first round of the men's table tennis.

British Prime Minister David Cameron called the incident an honest mistake and said he was sure there would be no repetition at the Games.

Earlier, in response to a question from Chang on the final day of the IOC session, president Jacques Rogge said there had been no "political connotation".

"The organising committee has taken corrective action and there will be no repeat. It was a simple human mistake," he said.

Greece, who banned triple jumper Paraskevi Papachristou on Wednesday after a racist tweet, suffered further embarrassment on Thursday when the father of world indoor high jump champion Dimitris Chondrokoukis said his son had pulled out of the Games after failing a doping test.

'Nothing to chance' 

Speaking to reporters at the Olympic Park, Cameron said the government's priority was to ensure a safe and secure Olympics, with more than 9,000 extra police walking the streets and 17,000 troops called in to cover a shortfall left by private security group G4S.

Security has been an overriding concern for the government and Games' organisers. The day after the British capital was
awarded its third Olympics in 2005, four suicide bombers killed 52 commuters in London.

G4S caused a scandal by failing to meet its target for the number of guards it could provide, and on Tuesday said that it had deployed around 5,800 security personnel, still short of its revised objective of 7,000.

"This is the biggest security operation in our peacetime history, bar none, and we are leaving nothing to chance,"
Cameron said.

"Obviously the biggest concern has always got to be a safe and secure Games. That matters more than anything else."

The penultimate day of the torch relay began on another sun-drenched day in Camden in north London and was due to finish at Westminster, home to Britain's parliament, in the afternoon, with tens of thousands flooding on to the streets to watch its progress.

"It's amazing, look, people are hanging out of the windows to watch," said 61-year-old sales assistant Ulla Davis.

"The country has always been enthusiastic, it's just the newspapers that have been against it."

Excitement over the Games has been visibly building, partially dampening down criticism that the huge costs and transport woes aren't worth it. Britain's capital will be the first city to host the Summer Olympics three times.

After the opening ceremony on Friday, attention will quickly focus on the sport, with the progress of swimmer Michael Phelps, looking bedraggled and scruffy when he appeared in front of the media three days before he enters his final Olympics, no doubt dominating the first week of the competition as he battles team mate Ryan Lochte for supremacy in the pool.

Phelps, who won a record eight gold medals in Beijing, will attempt seven events before he retires - his career
achievements demonstrating that individuals are still at the beating heart of the Games.

The highlight of the Games is likely to be the men's 100 metre final on August 5, when Usain Bolt and seven other men compete for the title of fastest man in the world.