ANTAKYA, Turkey, Feb 23: Turkey has stepped up plans to house victims of the devastating earthquake which struck its border region with Syria, the interior minister said, as the combined death toll in the two countries crept towards 50,000.

Suleyman Soylu said 313,000 tents had been erected, with 100,000 container homes to be installed in the disaster zone which stretches for hundreds of kilometres inland from the Turkish and Syrian Mediterranean coast.

The number of people killed in Turkey has risen to 43,556, Soylu said, while in Syria the death toll was close to 6,000. The United Nations said more than 4,500 were killed in Syria's rebel-held northwest, and the Syrian government said 1,414 people died in the area under its control.

Soylu said more than 600,000 apartments and 150,000 commercial premises had suffered at least moderate damage.

"Our cities will be built in the right places, our children will live in stronger cities. We know what kind of test we are facing, and we will come out of this stronger," he told state broadcaster TRT Haber.

Soylu also said authorities were widening an investigation into Turkish building contractors suspected of violating safety standards and multiplying the scale of devastation.

He said 564 suspects had been identified, with 160 people formally arrested and many more still under investigation.

Turkey's President Tayyip Erdogan, in power for two decades and gearing up for elections within four months, faces accusations from opposition parties that his own government failed to enforce building regulations.

Even before the magnitude 7.8 quake struck on Feb. 6, opinion polls showed he was under pressure from a cost of living crisis, which could worsen as the disaster has disrupted agricultural production in southern Turkey.

Erdogan has pledged to rebuild housing within one year.