Residents retrieve items from the debris of a house that was damaged in Kathmandu, Nepal's capital, during Saturday's magnitude-7.9 earthquake, revised down from 8.1 earlier. BERNAT ARMANGUE / AP

The relief operation for Nepal earthquake victims intensified on Monday, with aid and personnel arriving from neighboring countries including China and India.

The international airport in Kathmandu, the capital of Nepal, has been operating normally since Sunday, with passenger planes and aircraft carrying relief supplies arriving from various countries worldwide.

However, some people — mostly Indian nationals — had been waiting at the airport for two days to be evacuated. Indian authorities said they had evacuated 1,935 stranded citizens in Nepal, with officials in New Delhi saying the Indian Air Force had flown 12 missions to bring residents home, including many children.

While thousands staying outdoors amid chilly weather and sporadic rain on Sunday night, life in Kathmandu was returning to normal with many people going back to work.

Shops and restaurants were starting to reopen and some hotels were arranging trips to mountain resorts for foreign tourists and trekkers.

The UN food agency said it was preparing a large-scale aid operation to Nepal, with the first plane due to arrive on Tuesday. "This will be a large, massive operation," said Elisabeth Byrs, spokeswoman for the World Food Programme.

Officials said more than 3,700 people are known to have died, most of them in Nepal, making it the quake-prone Himalayan nation's deadliest disaster in more than 80 years.

World Food Programme experts arrived in Kathmandu on Sunday to assess the situation, with the agency saying that shelter and medical equipment should be the first priority.