Emergency crews are taking part in a large-scale disaster drill in southeastern England, complete with blood-covered "victims," trapped in rubble and mangled subway carriages in an Underground station.

The training exercise Monday re-creates Waterloo Station in the aftermath of a building collapse.

The set for the four-day drill was created at a disused power plant and took a year to plan.

Dozens of photographers lined balconies above the wreckage to watch as some 250 police, firefighters and ambulance workers practiced dealing with an emergency of 1,000 or more casualties.

The scene also included a specially constructed temporary mortuary to test victim identification.

London Fire commissioner Ron Dobson says the response will be "rigorously observed" by independent evaluators so lessons can be learned.