Coe responded to widespread criticism after the first full day of competition by predicting that seats left unused, largely by Olympics and sports officials, will stop being an issue as the games move through the preliminary rounds.
"It is obvious, some of those seats are not being used in the early rounds so that's where we put the military in there. That's why we have students and teachers in there," Coe said at a briefing.
He declined to blame Olympic sponsors, whom he had earlier promised to "name and shame" if they did not use their allocations.
Sponsors including Coca-Cola and Visa defended how they used their quotas, which amount to eight per cent of the 8.8 million available tickets, Coe said.
The issue is sensitive for Olympics organizers and British sports fans after hundreds of thousands of people failed to get tickets in an initial public ballot.
"There is not a single person who thinks it is shambolic," Coe insisted, adding that no one would object to free tickets for military personnel who "stepped up to the mark" this month to help solve a security staffing crisis at venues.
Coe's organizing team has long promised to fill venues and avoid having empty seats, as was the case in the 2008 Beijing Olympics.
He said he was "jammed in shoulder to shoulder" with Olympic officials at swimming finals on Saturday evening, and pointed to record crowds lining the men's road race route, and for rowing events at Eton Dorney.
"Those venues are stuffed to the gunnels," Coe said.
Yet broadcast images of such signature Olympic events as gymnastics and swimming revealed rows of empty seats for qualifying rounds on Saturday. Tennis matches at Wimbledon's Centre Court were sparsely attended just weeks after the iconic Grand Slam event there was completely sold out.
Army personnel were attending gymnastics sessions Sunday morning at the North Greenwich Arena during down time from security duties.
"There are a whole bunch of the military actually sitting in those seats at the moment. We can and we have moved them in there," Coe said.
Students and teachers from east London neighbourhoods also will get late calls for free tickets having already been accredited in a planned reallocation program. Some ticket holders will get upgrades inside venues, Coe added.
Some of the blame for the opening day embarrassment was falling on "accredited people" — including the Olympic family, athletes, and some sponsors and media, organizers said.
Coe said it was typical at the Olympics for sports and national team officials to be "dragged to any number of venues," and be too busy to attend events in the opening days. "I don't think you will be seeing this as an issue long-term during the games."
Sponsors, whose legal rights to protect their brand at the Olympics often fuel criticism, also were defended by the organizing committee chairman.
"I am not sure naming and shaming is what we are into at the moment. Sponsors are turning up," Coe said.
British Culture Secretary Jeremy Hunt had said late Saturday that the no-shows probably corporate guests.
"We think it was accredited seats that belonged to sponsors," Hunt said. "But if they're not going to turn up, we want those tickets to be available for members of the public, because that creates the best atmosphere."
Coca-Cola and Visa said they gave most of their allocated seats to prize winners in promotional offers.
Coca-Cola said its competitions allowed people "to choose the event they really wanted to attend."
"We have also invited some long-standing partners, employees, and customers to attend the Games. We believe that usage levels of our tickets have been extremely high so far," Coca-Cola said in a statement.
Visa said it made "great efforts to ensure that our ticket allocations are fully used."
Organizers will continue to offer more opportunities for people to attend Olympics events.
Releasing tickets for walk-up sales allowed about 1,000 seats to be sold for gymnastics on Saturday, and the Wimbledon policy of "recycling" tickets has been adopted.
Coe said almost 300 people saw handball matches on Saturday by buying cheap tickets — 5 British pounds ($7.87) for adults, 1 pound ($1.57) for children — which were handed in for re-sale by the original holders upon leaving the venue.
Graham Dunbar can be reached at www.twitter.com/gdunbarap
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