Further deaths from an outbreak of Legionnaires' disease cannot be ruled out, doctors said yesterday as the number of cases rose by 10 to 61.

There were 24 confirmed and 37 suspected cases of the infection, with 12 people in intensive care. One man has died, named as Robert Air, 56, from Seafield in Edinburgh, where the outbreak started. Dr Duncan McCormick, of NHS Lothian, said: "We can't rule out further deaths."

Two patients are being treated outside the NHS Lothian area – in the Scottish Highlands and in the North of England. The source has not been identified, but chemical treatment was under way at cooling towers in an Edinburgh industrial area where the outbreak is centred.