It is no secret that people in London have links with terrorists abroad. What is causing concern now is that those people are regarding the capital as a target and not just a hiding place. There was an alert just before Christmas because there was evidence of an attack. Nothing happened, but that doesn't mean we are safe. Scientists said the chemical was easy to manufacture and a tiny amount released in an underground station could kill thousands of people.
Terrorist groups are increasingly keen to experiment with chemical weapons.
Sarin, which is 26 times more deadly than cyanide, is particularly sought after because, being odorless, it is almost impossible to detect. It was developed as a chemical weapon by the Nazis during World War II and its potential for terrorist use was realised in 1995 when the Japanese cult Aum Shinrikyo used it during an attack on an underground train. Twelve people were killed and more than 5000 injured. In 1999, as a direct result of the Tokyo attack, police in London set up a unit to advise key installations on how best to safeguard themselves from a chemical attack. The Age Company Ltd 2001.