Facing criticism for swaths of empty seats at venues, Olympic organizers said Tuesday that 2.1 million people attended events in the first three full days of competition.
They said 86 percent of ticket-holders showed up Saturday, 92 percent Sunday and 88 percent Monday.
The empty seats have been blamed mostly on officials from sports' governing bodies and national Olympic committees that don't use their tickets in prime areas, which are often seen on television and in photos.
Organizers say 856,000 attended events Saturday, including a "conservative" estimate of 500,000 on the men's cycling road race route.
It was 900,000 on Sunday, when eight men's soccer matches were played. An estimated 300,000 lined the women's cycling route. Monday's overall attendance was 370,000.
Organizing committee spokeswoman Jackie Brock-Doyle said it won't publish breakdowns of each sport's attendance, which could detail events that struggled to lure ticket-holders.
The signature Summer Games sport, track and field, will "face the same problem in the Olympic Stadium," when events begin Friday, the president of its governing body acknowledged.
"We will do our best. I hope we will succeed to make this stadium full and make you forget about the other ones," IAAF President Lamine Diack told reporters Tuesday. "The public seats will certainly be full."
As for the empty seats, a potential solution was offered Tuesday when the head of Britain's Olympic body called on the IOC to take more responsibility.
The International Olympic Committee should invest hundreds of millions of dollars in centralized ticket distribution, British Olympic Association chairman Colin Moynihan said.
"It is so important to the sporting public of the host city, the host country, to get this right that this is now, I hope, recognized by the IOC as something which they should take on," Moynihan said at a news conference.
Moynihan said the proposal had not been given to the IOC, but should be part of a formal debriefing of the London Olympics hosted by 2016 host Rio de Janeiro in November.
The logistics challenges facing London Games organizers, and the "very regrettable" images of under-occupied venues, were an unfair burden, Moynihan said.
Ticket sales are the responsibility of the organizing committee, which pledged that 75 percent would reach British residents.
Reacting to problems during the weekend, organizers now contact sports officials each evening to reclaim prime seats for sale online.
Brock-Doyle said 3,800 tickets, covering 30 sessions across 15 sports, were quickly sold to the British public for Tuesday events. Buyers for events in Olympic Park, North Greenwich Arena and volleyball venue Earls Court will also be allowed to print out their tickets at home.
Troops on downtime from Olympic duties and pre-accredited students and teachers are also being given tickets.
IOC spokesman Mark Adams said its operations are "constantly under review."
