Live pigs are being blown up with explosives at Porton Down, the U.K.'s secret military research laboratory, to simulate the effect of terrorist attacks on civilian targets.

In a series of tests at the biological and chemical research centre in Wiltshire, 18 large pigs were wrapped in protective blankets before bombs were detonated a few feet away. The scientists allowed the pigs to bleed until almost a third of their blood was gone to see how long they could be kept alive.

MPs and animal welfare groups have questioned the use of live animals in the explosions, even though the pigs were anaesthetised throughout. None survived the experiments.

Norman Baker, the Liberal Democrat MP for Lewes, said: “These are revolting and unnecessary experiments. Sadly, we are too familiar with the effects of terrorism. It is perfectly possible to find out things we don’t know without blowing up pigs to find out.”

Research papers, obtained by The Sunday Times, show that the experiments at the Defence Science and Technology Laboratory were carried out because “blast injuries are an increasing problem, owing to the widespread terrorist threat”.

The blasts were meant to recreate the effect of an explosion in an enclosed space, such as the July 2005 attacks on the Underground and a double-decker bus in London, and had been designed to help medics control haemorrhaging from victims.

The pigs were wrapped in Kevlar blankets to protect them from minor bomb debris and placed less than three yards from the explosive. Before being blown up, they had tubes inserted into their blood vessels and bladders, and their spleens removed. A major blood vessel in the abdomen had a wire put into it so the vessel was lacerated during the blast.

Porton Down said the research programme would help British soldiers exposed to bombs in Afghanistan as well as potential civilian terror casualties. Up to 94 percent of critically injured victims of the 2004 Madrid train bombings were identified as suffering from “blast lung”, an injury that leaks over time.

A spokeswoman said that anecdotally there was already evidence that the research was helping to save lives.

“This work is part of our broad combat casualty care programme. Anecdotally, we are seeing evidence of people surviving because of this work,” she said.

Click here for the full report from the Times Online.