Pallade Veneta - 100 missing after flash flood washes out Indian Himalayan town

The roaring waters tore down a narrow mountain valley, demolishing buildings as the flood barrelled into the town of Dharali in Uttarakhand state.

"It is a serious situation," Minister of State for Defence Sanjay Seth told the Press Trust of India (PTI) news agency.

"We have received information about four deaths and around 100 people missing. We pray for their safety."

Videos broadcast on Indian media showed a terrifying surge of muddy water sweeping away multi-storey apartment blocks in the tourist region.

Several people could be seen running before being engulfed by the dark waves of debris that uprooted entire buildings.

Uttarakhand State Chief Minister Pushkar Singh Dhami said rescue teams had been deployed "on a war footing".

- 'Wake-up call' -

India's army said 150 troops had reached the town, helping rescue around 20 people who had survived the wall of freezing sludge.

"A massive mudslide struck Dharali... triggering a sudden flow of debris and water through the settlement," the army said.

Images released by the army, taken from the site after the main torrent had passed, showed a river of slow-moving mud.

A wide swath of the town was swamped by deep debris. In places, the mud lapped at the rooftops of houses.

State Disaster Response Force commander Arpan Yaduvanshi said the mud was 50 feet (15 metres) deep in places, swamping some buildings entirely.

"Search and rescue efforts are ongoing, with all available resources being deployed to locate and evacuate any remaining stranded persons," army spokesman Suneel Bartwal said.

Prime Minister Narendra Modi expressed his condolences in a statement, and said that "no stone is being left unturned in providing assistance".

Chief Minister Dhami said the flood was caused by a sudden and intense "cloudburst", calling the destruction "extremely sad and distressing".

The India Meteorological Department issued a red alert warning for the area, saying it had recorded "extremely heavy" rainfall of around 21 centimetres (eight inches) in isolated parts of Uttarakhand.

Deadly floods and landslides are common during the monsoon season from June to September, but experts say climate change, coupled with urbanisation, is increasing their frequency and severity.

The UN's World Meteorological Organization said last year that increasingly intense floods and droughts are a "distress signal" of what is to come as climate change makes the planet's water cycle ever more unpredictable.

"The devastating loss... must be our final wake-up call", said climate activist Harjeet Singh, from the Satat Sampada Climate Foundation in New Delhi.

"This tragedy is a deadly cocktail", he added.

"Global warming is super-charging our monsoons with extreme rain, while on the ground, our own policies of cutting hills; unscientific, unsustainable, and reckless construction; and choking rivers for so-called 'development' are destroying our natural defences."

I.Saccomanno--PV