Three people have died and 71 others were admitted to hospitals in Rzeszow in south-east Poland following a Legionnaire's disease outbreak, local health authorities said Wednesday.

The local authorities in Rzeszow have called in an emergency meeting to determine the cause of the contamination which is not yet known.

"Three people died of legionellosis," a spokesperson for the university hospital in Rzeszow told AFP, adding that the victims were all elderly people.

The health authorities said in the statement that 71 people were hospitalised, having been infected with the bacteria that causes pulmonary issues, especially for people with weak immune systems.

Local officials announced additional disinfection works and checks in the municipal water supply network, with the first sample results to be known Monday.

Legionnaire's disease is not contagious and cannot be spread directly from person to person, but can multiply in water and air-conditioning systems.