Two people have died and around 150 are ill after an outbreak of Legionnaires’ disease in the German town of Warstein.

It is one of the worse outbreaks of the disease in the country.

Experts believe that the source was the water treatment plant in the town. Legionella bacteria was found in the cooling system there.

The mayor and local authorities have been trying to reassure the population, telling them the illness can not be transmitted by drinking water.

Dr. Martin Lexner from the Hygiene Institut said: “It is the most significant illness to be caused only by environmental factors. It is not transmitted from person to person. So we do not need to isolate patients in the hospital who suffer from legionella because they are not a source of infection.”

Legionnaires’ disease is a potentially fatal form of pneumonia caused by legionella bacteria. Initial symptoms include a high fever, muscle pain and vomiting. It is usually caught by breathing in small droplets of contaminated water.