The rescue operation for a boy who fell into a deserted well in Li County, Hebei province is underway on November 6, 2016. [Photo: Xinhua]

The rescue operation for a five-year-old boy who has been stuck for three days down a 40 meter deep abandoned well that is no wider than a ruler, in Hebei province is still underway.

The boy fell into the well in Baoding on Sunday morning, and rescue staff at the site said the digging machines are still seven meters from the bottom of the well and the boy.

It is estimated the work will take only a few hours more, as the digging machines have passed through the hardest layer of soil.

Earlier reports said at least 80 excavators and 100 dump trucks are being used at the site.

No sign of life has been detected from the boy since rescue operations began, but he has been supplied with oxygen, food and water.

The well had been left unused for five years and there were no warning signs.