Thousands of small communities in earthquake-hit Nepal have not yet been reached by a rescue operation that could take weeks.

Many of the tiny villages clinging to steep hillsides across the country were hit by landslides caused by the first tremors, or a series of aftershocks that followed.

Rescue helicopter teams from the Indian army have been flying sorties throughout the day, Sky New reports.

The aircraft was packed with water, rice and tents - vital supplies that could be the difference between life or death for the survivors in the days to come.

Major Shiv Sangakara was weary from the sorties but said that without the help of his army team the situation would be much worse.

He said: "This is a very prominent area and it has been badly affected. This is the area where the river flows and there are hydropower projects, so because of this earthquake there's been a lot of damage to life as well as property."

Each time the helicopter makes an aid delivery, it picks up injured earthquake victims and transports them to Kathmandu, where a military field hospital has been set up near the airport.

But facilities are basic at best.

Captain Gurav Taneja told Sky News the situation is desperate.

He said: "The injuries are mostly musculoskeletal, mostly fractures and backbone trauma or head injuries. These injuries have occurred due to heavy falling objects."

Dendra, 12, was rescued from one of the small hill communities after suffering a severe head injury.

Stranded after the earthquake, he had had nothing to eat or drink for days.

His grandfather Renjan was barely alive and medics on board the helicopter feared his weak breathing suggests that he may not survive.

When we landed back in the capital it was clear that Dendra was badly concussed.

The doctors said he would make a full recovery - but the fate of many of Nepal's people is still unknown.