Potentially dangerous bacteria have been found in the water supply serving a special needs academy and youth club in Tufnell Park.

Health inspectors were called to The Bridge Secondary School - part of a multi-academy trust - in Carleton Road yesterday due to "low levels of Legionella bacteria" being found in the school's water. Legionella have also been found in water at a sports facilities managed by The Bridge and used by Beacon High secondary school (until recently called Holloway School), and at The Zone Youth Club in Carleton Road.

Legionella can cause a rare form of lung infection pneumonia called Legionnaires' disease, which becomes hazardous when bacteria in water droplets becomes airborne and is inhaled. But The Bridge London Trust's chief exec Dr Penny Barratt says there's "no need for alarm" and that experts have said the school is safe.

Unison's branch secretary in Islington Jane Doolan told the Gazette yesterday: "This is terrible. If there is Legionnaires' disease the building should be evacuated and the students and staff should all be tested. They all need medical advice at the least."

She later added: "I talked to our rep at The Bridge and said there was suspected Legionnaires' disease and health and safety are there at the moment putting in some temporary measures; doing risk assessments and tests."

A spokesperson for the Health and Safety Executive (HSE) said: "HSE is aware and is making initial inquiries."

An anonymous whistleblower contacted the Gazette to voice their "concern" about the alleged outbreak at the school yesterday morning.

They said: "It's likely they have Legionnaires' but they have kept staff and students in school. They are not allowing students to use hot water. It's really bad.

"It's not clear how long the head has known and, from what I have been told, not all the staff have been informed about it."

Legionnares' disease can be caught through infected tap water, toilets and air conditioning systems. The NHS website says it's "uncommon but can be serious".

After repeated requests for urgent comment yesterday, Dr Barrat today said: "As part of routine tests of the water low levels of Legionella bacteria were found in the water system serving The Bridge Secondary School, the sports facilities at Beacon High School, The Zone Youth Club and the swimming pool on the site.

"Immediate action is being taken to address this situation, and there is no need for alarm. The whole water system is being disinfected and a number of other preventative strategies put in place. Advice has been provided by experts and all recommendations are being fully implemented.

"The water will be retested on Monday, and results will be known 12 days later. As a precaution, the swimming pool on site will be closed for the next two weeks and there will be no access to the showers.

"Expert advice indicates that the buildings are safe to remain open and activities within them can continue as normal. The drinking water remains safe."

The Gazette has asked Dr Barratt when the trust discovered the Legionella, and which "experts" it's employing to deal with the problem.

Beacon High's executive headteacher Jo Dibb said: "Traces of Legionella were found during routine testing of the sports facilities managed by the Bridge School. There is no connection between the water supply in the facilities and the water supply at Beacon High. We will not be using the facilities until the problem has been resolved."

If you've been exposed to Legionella and have a bad cough that won't go away, cannot breathe properly, have severe chest pain, a high temperature and shivers, or flu-ike symptoms, the NHS advises you to call 111.