SWAT teams fast-roped down from a Blackhawk helicopter to storm a building -- represented by a fenced-in area on the football field -- believed to be a terrorist safe-house used to store an explosive device and radioactive materials.

The teams from Miami police and the FBI arrested several of the seven people inside the ficticious building, while some of the terrorists faked being shot dead, causing chuckles among some of the participants in a weeklong conference on nuclear terrorism who attended the event.

A remotely controled robot blew up the explosive device, and the delegates watched from the comfort of the air-conditioned VIP lounge as a bomb-squad specialist inspected the scene, wearing almost 40 kilos (80 pounds) of protective gear in temperatures that soared around 30 degrees centigrade (86 degrees Fahrenheit.

"We know that there are terrorists out there who would love to be able to take any kind of nuclear weapon and detonate it," FBI spokeswoman Judith Orihuela told journalists during the demonstration.

"So we know this scenario could happen and we'll do anything we can to prevent it," she said.

The Miami conference is attended by officials from some 30 nations that signed on to the Global Initiative to Combat Nuclear Terrorism announced in July 2006 by US President George W. Bush and his Russian counterpart Vladimir Putin.