Mossad officials participated in a security drill at London's Olympic Park last weekend.
A source at the British Cabinet told Yedioth Ahronoth that the drill simulated a terrorist attack on athletes, similar to the one that occurred in the Munich Olympics in 1972, when Palestinian terrorists took over the building where the Israeli delegation was staying, and killed 11 of them.
The UK's entire defense establishment, including the emergency services, participated in the massive drill, which was held secretly by the British Defense Ministry.
But British intelligence officials were not satisfied, and invited their Mossad counterparts to share their experience.
Source and full story: YNet, May 12 2011