23 Indian soldiers disappeared after a cloudburst on Wednesday caused a flash flood in the northeastern state of Sikkim, according to a defence spokesperson who spoke to Reuters. The state capital of Gangtok, which is located close to the border with China, is 150 kilometres (93 miles) to the north of the valley where the flood occurred. The spokesperson, who was based in Guwahati, said that some military installations in the valley were affected and that efforts were being made to learn more about the circumstances. “Some army establishments along the valley have been affected and efforts are on to confirm details,” said the spokesperson based in the city of Guwahati. Following the release of water from a dam, some vehicles were submerged by rising water, the spokesperson added. Under the condition of anonymity, an army official told Reuters that intermittent rain and thundershowers were impeding rescue efforts in the region. The river was already over 4.5 metres (15 feet) higher than usual, according to the army, due to water released upstream from the Chungthang dam. An Indian army spokesman released a video that showed a thick torrent of raging brown water sweeping down a densely forested valley, washing away roads and tearing down power lines. The monsoon season, which starts in June and typically ends by the end of September, is when flash floods frequently occur. The heaviest monsoon rains typically end by October. Experts claim that both their frequency and severity are rising due to climate change. Prem Singh Tamang, the chief minister of Sikkim, was seen in local media talking to officials about floods in the town of Singtam, which is further downstream from where the soldiers are missing while holding an umbrella during a downpour. The monsoon occurs when the subcontinent is warmed by summer heat, causing the air to rise and draw in cooler winds from the Indian Ocean, which then produce copious amounts of rain. However, it also brings yearly devastation in the form of floods and landslides.