A spokesman for the Austrian army said that there had been "clashes between groups," without giving details.

He told AFP the 82 soldiers from the Austrian Forces Disaster Relief Unit were sheltering in the southern Hatay province "in a base camp with other international organisations, awaiting instructions".

They had arrived in Hatay on Tuesday with 45 tonnes of equipment and were able to rescue nine people from rubble.

They were set to return to Austria on Thursday, but this is being reviewed, he said.

A similar decision to halt rescue operations was taken in Germany by the Federal Agency for Technical Relief (TSW) and an NGO specialising in helping victims of natural disasters, ISAR Germany, according to an NGO spokesman.

"In recent hours, the security situation in Hatay province has apparently changed," said ISAR spokesman Stefan Heine. "There are more and more reports of clashes between different factions, shots have also been fired."

German teams "are remaining in the common base camp for now as a result" and will resume their search when Turkish civil protection authorities "believe it sufficiently safe."

The 7.8-magnitude tremor has claimed almost 25,000 lives in Turkey and neighbouring Syria.