Photo: The Canadian Press

Spanish officials say rescuers are making slow progress in exceptionally difficult conditions to reach a 2-year-old boy who fell into a narrow, deep borehole in the countryside eight days ago.

Angel Garcia, the leading engineer co-ordinating the search-and-rescue operation, says work had to stop briefly early Monday to perform maintenance on a drill being used to create a vertical shaft.

Garcia says the rocks are extremely hard and the drill has been working nonstop for many hours.

The shaft runs parallel to the borehole and aims to go down 60 metres — roughly to where the boy is believed to be.

The drill has so far reached 53 metres. After that, miners will be lowered down the shaft to dig a horizontal tunnel to the boy's presumed location.