Thailand\'s prime minister warned Friday that Bangkok was under threat from the country\'s worst floods in decades as the authorities stepped up efforts to protect the capital and key industrial areas. \"The flooding situation is now considered a serious crisis,\" Prime Minister Yingluck Shinawatra said in a nationally televised address, noting that 252 people have died across the country due to more than two months of heavy rains. While the capital has so far escaped major flooding, Yingluck said the city of 12 million people would not escape unscathed. \"It is going to directly affect Bangkok,\" she said. Homes, roads and factories are already inundated just north of the low-lying capital and more storms are expected in the days to come. Many residents in affected areas have ignored the government\'s appeal to evacuate to safe areas, preferring to stay and guard homes submerged by the rising waters. The authorities raced to put up flood walls alongside canals and rivers on Bangkok\'s northern outskirts as huge amounts of muddy water flow down river. \"Nothing could be worse than the current situation, but the most important thing is to prevent flooding in Bangkok and two industrial estates\" north of the city, said Science and Technology Minister Plodprasop Suraswadi. A key test is expected in mid-October, when large amounts of run-off water reach the capital and high tides make it harder for the floods to flow out to sea. \"Every canal in Bangkok is already at full capacity. If more rain comes it\'s likely that Bangkok will be inundated,\" Bangkok governor Sukhumbhand Paribatra said on television. He said the city was preparing emergency stocks of food and drinking water, and setting up evacuation centres at schools. The floods -- several metres deep in places -- have damaged the homes or livelihoods of millions of people in Thailand, particularly farmers, according to the government. The military has been deployed to help victims and army camps are being opened to evacuees. Japanese car giant Honda has suspended production temporarily after its parts factories was inundated in Ayutthaya, the ancient capital just north of Bangkok. According to economists at the University of the Thai Chamber of Commerce, the damage amounts to 104 billion baht (3.4 billion dollars) in terms of the impact on buildings, crops, livestock, industry, tourism and trade. It said the impact could knock about one percent off the country\'s annual economic output. With more storms forecast, the fear is that the economic costs could rise if the waters reach the capital\'s business and economic hub. \"Certainly Bangkok will be flooded. We have to assess the situation after each storm,\" said independent expert Royal Chitradon, director of Thai Integrated Water Resource Management. Bangkok, located on the gradually sinking Chao Phraya delta, has been classified by the Organisation for Economic Co-operation and Development as one of the cities most at risk from coastal flooding by 2070.