'Gas odour'

The dormitory was being used by students aged eight to 16 who were taking part in a course of Islamic study.

Merve Avci, a 13-year-old student who suffered slight injuries, told reporters she had smelled gas coming from downstairs to the upper floors, and then felt the explosion.

"I was in the uncollapsed part of the building with five of my friends immediately after the explosion, and we felt flames rising from the downstairs to upper floors," she said, according to Anatolian news agency.

"Before the explosion, I heard one of our teachers saying that a gas hose was not attached to its proper place in the kitchen," Avci said.

Medical rescue teams were at the scene and had pulled out one of three girls they had established contact with under the rubble.

"We think the collapse was caused by a gas canister explosion in the building, given the burns on the injured," Galip Sef, a Konya health service official, said, according to Anatolian news agency.

The agency said the three-storey building belonged to a religious foundation.

Al Jazeera's correspondent Hoda Abdel Hamid said the collapse occurred when most of the girls were still asleep.

"Some girls told the local authorities they smelt gas odour in the dorm and one girl said the blast had occurred just after one of their fellow students turned on the switch light," she said.

"Local authorities are saying that rescue operations are continuing, some sniffer dogs were brought in and the mayor said that he has heard some voices from under the rubble."