Canterbury Cathedral was evacuated today after a man was seen to drop white powder in a chapel.
Police said a man reportedly dropped a small quantity of the powder in a chapel in the crypt of the cathedral.
A police spokeswoman said: "The man was spotted but no citizen's arrest was made. When police arrived he could not be found. We are actively searching for him.
"We do not want to jump to any conclusions at this stage."
Britain is on heightened alert over fears of biological attack after last month's terrorist atrocities in the United States and the US-led military reprisals against Afghanistan which began a week ago.
The cathedral, in the town of Canterbury east of London, is the seat of the Archbishop of Canterbury, the primate of the Anglican Church around the world.
Police said a cathedral worker spotted the man dropping the powder.
Firefighters wearing chemical protection suits were attempting to clear up the powder, and taking samples for analysis.
The spokeswoman added: "We are taking every precaution at this stage and so we have sent in firefighters with protective suits. It is still too early to say exactly what the powder is."
AFP