debris

A section of roof at the Royal Darwin Hospital collapsed, with bricks and debris littering a corridor floor.

Even so, the researchers cannot completely rule out that it might instead be a cluster of loosely bound debris.

Sarker told the BBC: "Our main task at the moment is to assess casualties and damage. We are not yet seeing the challenge of rescue from the rubble or debris management at that level."

Mohammad Sharif, who was in a queue to buy meat, said the debris fell from above on people standing ahead of him.

Teams are also working on clearing out debris and unexploded ordnance, the officials said.