Rescuers inched closer Friday to reaching a five-year-old boy trapped for three days in a well in Morocco, in an operation hampered by concerns about ground stability that has captivated the North African country.

The boy, identified as Rayan, fell into a 32-metre (105-feet) shaft, located outside his home in the village of Ighran in the northern province of Chefchaouen, on Tuesday evening.

Search crews first used five bulldozers to dig vertically to a depth of more than 31 metres, according to Morocco's official MAP news agency. 

Then on Friday, they started excavating a horizontal tunnel to reach the trapped boy, MAP said, adding that experts in topographical engineering were called upon for help. Work had to be temporarily halted, but was later resumed.

'Digging has stopped momentarily out of concern that the ground surrounding the well could collapse,' rescue committee member Abdelhadi Temrani told local television 2M.

Rescue workers used a rope to provide oxygen and water to the boy, but were unable to reach him via the hole where he is trapped due to its narrow diameter.

'I pray and beg God that he comes out of that well alive and safe,' his mother Wassima Kharchich told 2M. 'Please God, ease my pain and his, in that hole of dust.'

Medical staff, including specialists in resuscitation, are on site to attend to the boy once he is pulled out, with a helicopter on standby to transport him to the nearest hospital.