At least eight people were killed in building collapses caused by heavy rain in the western Indian city of Mumbai. Six people died when a six-storey residential building collapsed in south Mumbai, fire and police officials said. Two people were declared dead on Thursday evening, and rescuers pulled four more bodies from the rubble during the night. Several people had been trapped under the debris and many more stranded in the portion left standing after the collapse, city fire chief P S Rahangdale said. "The risk of secondary collapse can't be ruled out," he said. Witness told local television stations that the dilapidated building was home to five or six families who had stayed on despite residents being advised to move out as it was under repair. Another building collapsed in the western suburb of Malad earlier, killing two, including a child, and injuring several. Weather officials had on Thursday upgraded an alert for Mumbai and surrounding areas from orange to red following intense rains in previous days. The annual monsoon rains regularly cause old or poorly built structures in India's financial capital to collapse. The eight people killed in Mumbai are among at least 221 who died as result of heavy monsoon rains across South Asia over the past month, officials said on Friday. More than 1 million people have been marooned in Nepal, Bangladesh and India and hundreds of thousands have fled their homes for higher ground. India's death toll stood at 101, including 16 people killed in floods and mudslides in the north-east. Nepal reported at least 117 deaths over the past month and Bangladesh reported three. Rains caused the Brahmaputra River, which flows through Tibet, India and Bangladesh, to burst its banks in India's Assam state in late June, inundating large swathes of the state, triggering mudslides and displacing about 3.6 million people, officials said. Vast tracts are still underwater, with 26 of the state’s 33 districts badly affected. Authorities rescued about 4,000 people trapped by the surging flood waters in various parts of Assam, said M S Mannivanan, chief of the state Disaster Management Authority. About 36,000 people whose homes were destroyed or submerged have taken shelter in nearly 300 government-run relief camps, he said. The floods also inundated most of India’s Kaziranga National Park, home to an estimated 2,500 rare one-horned rhinos. In the eastern state of Bihar, at least nine rivers swollen by heavy downpours in Nepal rose beyond their danger levels and flooded many villages. One of them, the Gandak River, swept away the connecting roads of a newly built multimillion dollar bridge in Gopalganj district, disrupting transportation in the area. The Meteorological Centre in the state capital, Patna, forecast heavy rain over the next 48 hours. Nepal’s Home Ministry said 117 people have died in monsoon-related incidents, including landslides in mountainous areas and flooding in the southern plains. At least 47 people were reported missing and 126 have been injured in the past month, it said. In Bangladesh, the Ministry of Disaster and Relief said at least three people died and more than one million people were marooned since floods hit the country late last month. Officials said heavy rainfall and the onrush of river waters from upstream India were creating havoc in Bangladesh, a delta nation of 160 million people that is crossed by 230 rivers. Bangladesh's Flood Forecasting and Warning Centre said on Thursday that flooding could worsen at the beginning of next week because of growing devastation in the vast region along the Brahmaputra and Teesta rivers. It said the situation would remain unstable over the next two weeks, causing further suffering for affected people. The monsoon rains that hit the region from June to September are crucial for crops planted during the season but often cause extensive damage.