MADRID (AP) — Rescuers in southern Spain said Sunday that the frantic effort to reach a two-year-old boy who fell into a narrow, deep borehole seven days ago has again been slowed by difficult terrain.

Provincial authorities said that a drill used to create a vertical shaft parallel to the waterhole has hit a rocky patch.

There has been no contact made with Julen Rosello, who fell into the 110-meter (360-foot) deep shaft a week ago during a family meal in the countryside northeast of Malaga.

At just 25 centimeters wide (10 inches), the borehole is too narrow for adults to enter.

The only sign of the toddler search-and-rescue teams have found so far is hair that matched his DNA inside the hole.

Rescuers hope to find him at a depth of 72 meters (236 feet), where a soil blockage has hampered efforts to go deeper.

A specially-made cage has arrived at the site, ready to lower mining rescue experts down the shaft. The experts then hope to dig a horizontal tunnel to the spot where they believe the boy is trapped in the borehole.

Angel Garcia, the leading engineer coordinating the search-and-rescue operation, said on Saturday that the horizontal tunnel would take at least another 20 hours to excavate.

People across Spain have been gripped by the plight of the boy and his family, as the rescue attempt has suffered agonizing delays due to the rocky terrain.