Rescuers are scrambling to reach people who have been stranded for days on their rooftops following two typhoons in a week. The authorities are still trying to evacuate people amid a threat of further flash floods and landslides in the aftermath of typhoon Nalgae. At least 52 people were killed and thousands made homeless after Typhoon Nesat hit the country on Tuesday. Nalgae has followed the same route, killing at least three people. The death toll is expected to rise following Nalgae\'s six-hour rampage on Saturday across areas of the main Luzon island already waterlogged by Nesat. Nalgae has now moved into the South China Sea and is heading towards southern China with winds of 81mph (130k/ph) and gusts of 99mph (160k/ph). Hundreds of residents in the farming town of Calumpit, north of Manila, have spent four days on the roofs of their homes to escape the rising flood waters - running short of food and water.Rescue workers on rubber boats could not reach them because of narrow alleyways, and two air force helicopters were deployed to drop water and food packs to the marooned villagers, the Associated Press reports. \"We have a very big problem here,\" Calumpit Mayor James de Jesus told ABS-CBN TV network. \"We\'re facing a long flooding\". Benito Ramos, of the Office of Civil Defense, was inspecting the situation in the town, and warned that more water - flowing down from the nearby Cordillera mountain range - could exacerbate the problem. He called on anyone \"refusing to leave their homes, to let the authorities evacuate them\". Nalgae made landfall in the eastern province of Isabela on Saturday. At its strongest it was packing winds of up to 195km/h (121mph). It followed the same route as Nesat, which had already affected more than 2.4 million people. More than a million people had moved into evacuated centres, while others sought refuge at the homes of relatives and friends. Thousands were reportedly trapped on the roofs of their homes as Nesat barrelled across the island. Provincial disaster official Raul Agustin told ABS-CBN television that marooned flood victims were often reluctant to leave for fear their homes would be looted. \"When we send out rescue teams to help them, they ask for food instead,\" he said. The Philippines suffers frequent typhoons, about 20 a year.