Indonesia earthquake slows efforts to rescue those trapped by school collapse

Rescuers battling to extricate students from the rubble of an Islamic school under construction that collapsed and killed at least six in Indonesia's province of East Java faced a harder task on Wednesday, a day after an earthquake packed the debris tighter.

The magnitude 6.5 quake complicated the rescue work by narrowing the room for manoeuvre, said Emi Frizer, an official of Indonesia's search and rescue agency.

"If the space was initially 50 cm (20 inches) high, it caved in to 10 cm (4 inches), and we fear it impacts the constriction of the victims," added agency chief Mohammad Syafii.

The earthquake struck the region of Sumenep, about 200 km (124 miles) from the school, injuring three people and damaging dozens of homes, authorities said.

"How to hold on to the targets' lives while still having the same access - that's going to take us a little longer," Emi said, adding that searchers had to be careful not to injure victims' limbs during their rescue.

Late on Wednesday, Bramantyo, operation director at the agency, said rescuers found that three more people died in the boarding school's collapse in Sidoarjo, about 780 km (480 miles) east of the capital Jakarta, bringing the death toll to six.

Five more people survived and have been evacuated, Bramantyo added.

The agency declined to say how many people were still missing after the search operation.

Another agency, for disaster and mitigation, has said 91 people were listed as missing, with 100 evacuated and dozens injured after the collapse during students' late afternoon prayers in a mosque on the lower floor. The building's upper floors were under construction.

Authorities have said the building's foundation could not support higher-level construction work.

"This is all foundational failure," Emi added.

An excavator and a crane were on-site to help rescuers shift rubble, but local official Nanang Sigit ruled out their use for fear it could set off a wider collapse.