A woman has died after her car became submerged during torrential rain in eastern Japan, as authorities warned of the threat of landslides following the heaviest rainfall on record in parts of the country.The woman, in her sixties, was declared dead after being found unresponsive in a submerged car at an underpass in Iwaki, Fukushima Prefecture, at around 7.50am local time on Monday, Kyodo News reported, citing the local fire department. Two people suffered minor injuries after falling amid the heavy rain in Chiba Prefecture, the prefectural government said.Heavy rain hit large parts of eastern Japan from the early hours of Monday, including Tokyo, Kanagawa and Chiba prefectures, disrupting train services and forcing some school closures. In Niijima, around 150km south of central Tokyo, 485mm of rain fell in the 24 hours to 9.40am, the largest amount there since local records began, the Japan Meteorological Agency said.Footage from a live camera showed a river in Yakushima, Kagoshima Prefecture, swollen by heavy rain over the weekend.The JMA issued Level 5 emergency landslide warnings, the highest on its five-point scale, for Niijima Village, Oshima Town and Toshima Village, part of the Izu Island chain south of Tokyo. Foreign tourists pull their suitcases as they walk along a street near Shinjuku Station in Tokyo (AFP/Getty)It issued a lower, Level 4 landslide alert for parts of Chiba and Saitama prefectures, neighbouring the capital.The central government has set up a liaison headquarters at the prime minister's office to assess potential damage and coordinate the emergency response.The weather agency warned of further heavy rain across wide areas facing the Pacific, as warm, damp air moves toward a rain front stretching along Japan's main island of Honshu. It also warned that prolonged, localised torrential downpours capable of causing significant damage could develop in the north-eastern Tohoku region as a seasonal rain front moves further north over the coming days.