Turkey vowed on Sunday to investigate thoroughly anyone suspected of responsibility for the collapse of buildings in the country’s devastating earthquakes nearly one week ago and has already ordered the detention of 113 suspects.

Vice President Fuat Oktay said overnight that 131 suspects had so far been identified as responsible for the collapse of some of the thousands of buildings flattened in the 10 provinces affected by the tremors early last Monday.

“Detention orders have been issued for 113 of them,” Oktay told reporters in a briefing at the disaster management coordination centre in Ankara.

“We will follow this up meticulously until the necessary judicial process is concluded, especially for buildings that suffered heavy damage and buildings that caused deaths and injuries.”

He said the justice ministry had established earthquake crimes investigation bureaus in the quake zone provinces to investigate deaths and injuries.

Environment Minister Murat Kurum said that 24,921 buildings across the region had collapsed or were heavily damaged in the quake, based on assessments of more than 170,000 buildings.

Rescuers were still looking for survivors in the earthquake rubble six days after the disaster, which hit parts of Syria and Turkey. The death toll has exceeded 28,000 and is expected to rise further.

Opposition parties have accused President Tayyip Erdogan’s government of not enforcing building regulations, and of mis-spending special taxes levied after the last major earthquake in 1999 in order to make buildings more resistant to quakes.

Erdogan has said the opposition just tells lies and spreads slander to besmirch the government, obstructing investment instead of facing up to corruption in the opposition-run municipalities.

In the 10 years to 2022, Turkey slipped 47 places in Transparency International’s Corruption Perception Index to 101, having been as high as 54 out of 174 countries in 2012.

State prosecutors in Adana ordered the detention of 62 people in an investigation into collapsed buildings, while prosecutors sought the arrest of 33 people in Diyarbakir for the same reason, state-owned Anadolu news agency reported.

It said eight people had been detained in Sanliurfa and four in Osmaniye in connection with destroyed buildings believed to have faults, such as columns being removed.

Police detained the developer of one residential complex which collapsed in Antakya at Istanbul Airport as he prepared to board a plane for Montenegro on Friday evening and he was formally arrested on Saturday, according to Anadolu.

The upmarket 12-storey residential complex was completed a decade ago and contained 249 apartments. There was no information on the casualties in that building.

The arrested man told prosecutors he did not know why the complex collapsed and that his desire to go to Montenegro was unrelated, Anadolu reported.

“We fulfilled all procedures set out in legislation,” he was quoted by Anadolu as saying in his statement. “All licenses were obtained.”