Damage after an explosion in the city of Belgorod.
"An explosion took place. According to preliminary information, there are no victims," Vyacheslav Gladkov, governor of the Belgorod region, said on the Telegram messaging app.
He added that a "huge" crater some 20 metres wide (65 feet) had appeared in the city centre.
Belgorod mayor Valentin Demidov arrived at the scene and posted pictures of damage on Telegram.
One picture showed him speaking to a local resident in what appeared to be her damaged apartment.
Neither the governor nor the mayor said what caused the explosion, but Gladkov said that the blast had sent a massive wave that shattered windows in an apartment building, damaged several cars and downed power line poles.
Demidov said that residents of the buildings damaged in the blast could be temporarily moved to hotels.
The Belgorod region, including the city of the same name, has been repeatedly hit by shelling since President Vladimir Putin sent troops to Ukraine in February 2022.
In January, Gladkov told Putin that 25 people had been killed and more than 90 injured in the region since the start of the offensive.