Thousands of extra Olympic tickets have gone on sale, as organisers try to defuse the row over empty seats at many venues.
Another 3,000 seats, including 600 for the gymnastics and 700 for beach volleyball, have been "put back into the pot", according to the organising committee, Locog.
A spokeswoman for the organisers said they had talked to international federations, whose allocations were believed to be responsible for most of the empty seats.
"We are doing it session by session talking to the accredited groups," she said. "Everybody is giving up what they can."
The row has also drawn in the British prime minister, David Cameron, who called the empty seats "disappointing" but "not a unique episode" when compared with other Games. The culture secretary, Lord Jeremy Hunt, also called the issue "disappointing", adding: "We want those tickets to be available for members of the public, because that creates the best atmosphere."
On Sunday, tickets were offered to schoolchildren, teachers and members of the armed forces on security duty to fill some of the gaps.
Several parents of competitors have complained they were not able to get seats. Police said they had arrested 10 people on ticket-related offences, including charges of ticket-touting, theft and handling stolen goods.
The arrests were part of the Metropolitan Police's Operation Podium, which aims to protect visitors to the Games.
One group was said to be impersonating police officers in a bid to convince tourists to had over cash and credit cards. Two arrests took place outside the beach volleyball at Horseguards Parade, with another near the canoeing at Lea Valley
Detective Superintendent Steve Osborn said: "Officers would never take money from you, they would never take you to a cashpoint and ask you for money.
"They are unlikely to ask to see your bank cards and would never need to ask you for your pin number."
