London - Prime Minister David Cameron says he shares British frustration at seeing empty seats in London Olympics venues but he believes organisers will soon improve the situation.The empty-seats problem has lingered beyond the first weekend of competition, taking some shine off Friday's opening ceremony, which was hailed with lavish praise from most British. Locals have been outraged at the television images of empty stands, since many had spent months trying - and failing - to buy Olympic tickets online."We can do better," Cameron acknowledged on Monday, after games organisers explained their range of tactics to fill the gaps with ordinary sports fans.Organisers needed to "make sure more people get to see more games and also that there are fewer empty seats", Cameron told broadcaster ITV in an interview.Speaking after a meeting of his government's Olympics panel, Cameron expressed confidence that the London organising committee was "on track" to meet his challenge.Military personnel, local students and teachers have all been offered Olympic tickets to get more fans immediately into the arenas.Extra ticketsAround 3 000 extra tickets were made available late on Sunday and quickly sold out for Monday's events, organising committee spokesperson Jackie Brock-Doyle said.Around 600 gymnastics tickets were freed up, plus 400 for morning sessions in beach volleyball and 200 more in the evening. Additional space was made for fans to see water polo, handball and equestrian events, she said.Organisers say seats were left empty mostly by accredited sports and national Olympic officials, athletes, some media, plus "a handful of sponsors". Sports governing bodies have been the main source for returning privileged-access tickets.Each evening, sports and national Olympics officials will now be asked to give back some tickets for fans to make late buys."We are doing it session by session," Brock-Doyle said. "We really are doing the best that we can."Ticket holders leaving an event are also being asked to "recycle" their ticket by allowing its resale for just a few pounds to a potential spectator already cleared by security inside the Olympic Park.Cameron accepted the efforts being made and said a perfect solution is unlikely."You can never solve the problem completely because there have to be some seats left for the accredited Games family," he said.