An earthquake of 5.7 magnitude has rocked Turkey’s southwestern city of Denizli, the country’s monitoring agency said on Thursday. The city’s mayor said there were no immediate reports of casualties, Reuters reports.

The Kandilli observatory had initially said the tremor measured 6.5 in magnitude. The earthquake occurred 8km (5 miles) below ground level. The US Geological Survey (USGS) said the earthquake had a magnitude of 5.8.

“There is no negative information from the center of Denizli so far,” Mayor Osman Zolan told CNN Turk television. “There are no reports of casualties so far,” officials have said, adding that special teams were working to assess the damage.