Nick Buckles spoke to the BBC as British newspapers were filled with accounts of chaotic recruitment, sloppy security, and even an allegation that some G4S staffers weren’t fluent in English. The firm has not been able to provide enough guards, and some 3,500 British troops are being called in to help fill the gap in security and police have been put on notice that they might need to help fill the breach.

“We’re deeply disappointed and we certainly are very sorry for what’s happened over the last week or two,” the chief executive said. “It’s a very complex process. No one’s ever undertaken to recruit 10,000 fully-trained security staff for such a lengthy period of time.”

Buckles said that the operation was a “mammoth undertaking” involving a complex recruitment operation in five or six different stages, adding that, as of Saturday, some 4,000 people were on the ground and that about 9,000 people were still in the pipeline

HIGH JUMP: Former world high jump champion Blanka Vlasic has withdrawn from the Olympics after failing to recover from injuries and health issues.

The 28-year-old Croatian dominated the high jump since her silver medal at the 2008 Beijing Games until ankle surgery last year.

In May, she said she was dealing with a bacterial infection that set back her recovery.

Vlasic said on her Web site that her “health situation is getting better,” but she won’t be able to get in top shape in time for the July 27-Aug. 12 Olympics.