sea quake. The federation said it would send medical supplies for 100,000 people in Sri Lanka -- close to the epicentre of one of the strongest quakes ever -- on Monday from Copenhagen, including special medication to treat diarrhoeal disease. "The biggest health challenges we face is the spread of waterborne diseases, particularly malaria and diarrhoea, as well as respiratory tract infections," the federation's senior health officer Hakan Sandbladh said in Geneva. The organisation said it would be sending a field assessment and coordination team to Sri Lanka within hours, and had on standby several emergency response units specialised on water and sanitation as well as field hospitals. Sri Lanka appears to be the worst hit but aid officials said the true scale of the disaster was yet to become clear. --More 2231 Local Time 1931 GMT