Slithering is an exercise where troops are dropped from a helicopter in an area of operation using a rope attached to the chopper.

A video clip circulating on social media appeared to show the accident.

Three soldiers sustained injuries during a heli-slithering drill at the Parade Ground in Delhi Cantt after the rope snapped, a person familiar with the matter said.

The soldiers were slithering down a Dhruv advanced light helicopter, rehearsing for the annual Army Day parade on January 15.

The soldiers are now out of danger.

The senior army officer said the force has ordered a probe into the accident and the activity will not feature in the line-up of events for the parade this year.

The officer said the mishap appeared to be the result of a material failure. “The soldiers fell on the ground after the boom broke off. One of them suffered serious injuries. They are all out of danger now,” he said.

The incident, captured on camera, took place on January 9.