By Shivam Patel

NEW DELHI (Reuters) -Torrential rain in India's Himalayas triggered landslides over the weekend that have killed over 50 people, with the death toll expected to rise as more than 20 remain trapped or missing, officials said on Monday.

Unusually heavy rain and melting glaciers have brought deadly flash floods to the mountains of India and neighbouring Pakistan and Nepal over the past year or two, with government officials increasingly blaming climate change.

Television footage from India's Himachal Pradesh state showed houses flattened by landslides, buses and cars hanging on the edge of precipices after roads gave way, and hundreds of people at rescue sites as emergency workers struggled to clear debris.

"Again, tragedy has befallen Himachal Pradesh, with continuous rainfall over the past 48 hours," the state's chief minister, Sukhvinder Singh Sukhu, said in a post on the messaging platform X, formerly known as Twitter.

More than 50 people had died in rain-related incidents within 24 hours, Sukhu told Indian news agency ANI, in which Reuters has a minority stake.

"This number can rise further because 20 people are still trapped," he said.

Officials from the state disaster management authority, meanwhile, said that 41 bodies had been recovered by Monday evening.

"Another 13 people are missing but, as time passes, we are losing hope that they will be pulled out alive," said state disaster management official Praveen Bhardwaj.

In one of the most deadly incidents, a temple collapsed in the state capital, Shimla, with rescuers pulling out at least nine bodies, the chief minister said.

In Solan district, houses collapsed, killing at least seven people, and a mother and her child were killed in Mandi district when their house collapsed, Bhardwaj said.

Television footage showed swollen rivers breaking their banks in Himachal and neighbouring Uttarakhand state, where also two people died and four were missing in incidents related to the rains, the Uttarakhand Disaster Management control room told Reuters.

The India Meteorological Department issued a "red alert" for both states on Monday and has forecast rainfall intensity to reduce from Tuesday onwards.

Parts of Himachal and Uttarakhand received as much as 273 mm (10.75 inches) and 419 mm (16.54 inches) of rain in 24 hours till 8:30 am IST (3 am GMT) on Monday, the weather office said.

Schools and other educational institutes were ordered to close in Himachal Pradesh and people in vulnerable areas were being moved to relief shelters, state officials said.

Uttarakhand state authorities announced that the Char Dham pilgrimage route would be closed until Tuesday following landslides.

(Reporting by Shivam Patel in New Delhi; Additional reporting by Saurabh Sharma in Lucknow and Sakshi Dayal in New Delhi; editing by Robert Birsel, Christina Fincher and Sharon Singleton)