More than 300,000 people have been forced out of their homes by flooding in Sri Lanka, with no sign of a let-up in the torrential rain on the island nation’s east coast.Three more people were killed by mudslides today, bringing the death toll to 21, officials said.The government’s Disaster Management Centre said more than 1 million people had been affected by the rains, with 325,000 made homeless.Many villages remain cut off from supplies despite a huge relief effort involving tens of thousands of troops, transport helicopters and naval boats. Map: Sri Lanka floodsThe deployment is the Sri Lankan military’s biggest since the end of the decades-long civil war against Tamil separatist fighters in 2009.Although senior officers reported that the flow of food to affected areas was going smoothly, senior local military officials reported that nine villages in the Muttur area of the eastern Trincomalee district were still cut off.According to Muhammad Jihad, a community leader, tens of thousands of people were in need of food and medical supplies, with stocks quickly running out.Across swathes of the east of the country, clean water supplies – usually wells – have been contaminated by the floodwaters, and there are fears of an outbreak of disease.“We are monitoring the situation very carefully. There are no signs of an outbreak so far, but there is always the threat,” Mervyn Fletcher, a spokesman for the United Nations Children’s Fund (Unicef) in Colombo, said.Unicef has sent 7,000 tarpaulins, as well as large quantities of water purifying tablets, to the affected areas.“Access to some of these areas is difficult at the best of times,” Fletcher added.Pregnant women and young children are already being taken to hospital to protect them from waterborne diseases in districts in which floods have brought sewage into the streets, Dharma Wanninayake, a spokesman for the ministry of health said.Many villagers remain in their flooded homes despite a danger from crocodiles and snakes. At least two people have been electrocuted.The Sri Lankan president, Mahinda Rajapaksa, has warned of a food shortage after tens of thousands of hectares of rice fields were inundated.Vegetable prices have risen sharply in recent days because distribution networks are blocked. Temperatures in Sri Lanka remained at historic lows, with more rain forecast.