Rescue operations have entered the third day after flash floods in India"s north-eastern state of Sikkim left over 100 people missing, including 22 army personnel. At least 19 people have died, officials said on Thursday night. The massive floods were trigged by a cloudburst over a mountain lake this week. The floods worsened after water was released from a nearby dam into the Teesta river. Hundreds of search and rescue personnel have been deployed across the state and areas near the river remain on high alert. More than 22,000 people have been affected by the floods with many stranded in Lachen and Lachung in northern Sikkim. The floods have disrupted mobile phone coverage in the area. "As per the data available, around 3,000 people are stranded in Lachen and Lachung," state chief secretary VB Pathak said in a statement on Thursday night. "We will evacuate all with helicopters of [the Indian] Army and the Air Force." The army said it was providing food and medical aid to people and extending communication facilities to civilians and stranded tourists. All schools and colleges in the state will remain closed until 15 October due to inclement weather. On Tuesday night, the state"s Lhonak lake breached its embankment after heavy rain, leading to an alarming rise in water in the Teesta river in Lachen Valley. The flood worsened after water was released from a nearby dam into the river. A defense spokesperson said there was a sudden increase in water levels up to 15-20ft high downstream. Satellite images shared by Isro, India"s space agency, showed dramatic changes in the volume of the lake. The lake covered an area of 167.4 hectares on 28 September, but by 4 October, it had shrunk to just 60.3 hectares. Pathak said the floods had caused massive damage to infrastructure, including roads and bridges. Northern parts of neighbouring West Bengal state have also been affected as water from the Teesta inundated Darjeeling, Kalimpong, Cooch Behar and Jalpaiguri districts. On Friday, the state government said two people were killed and six others injured after a mortar shell, found in the overflowing river, blew up in Jalpaiguri. Sikkim in the Himalayas is prone to floods and natural disasters. Last year, severe flooding there displaced tens of thousands and killed at least 24 people. — BBC