Russian officials said on Thursday their forces had destroyed 113 Ukrainian drones overnight, some of them having targeted an oil refinery in the northwest that resulted in a fire in a storage tank.
The sides finished two days of US-brokered talks in Geneva on Wednesday, trying to find a settlement to four years of war.
Both sides described the meeting as "difficult" and no breakthrough was announced.
During the night from Wednesday to Thursday, Russian forces "intercepted and destroyed 113 Ukrainian drones", the defence ministry said in a statement.
One of the drone attacks targeted an oil refinery in Velikiye Luki around 500 kilometres (300 miles) west of Moscow, causing "a fire in an oil storage tank", regional governor Mikhail Vedernikov said in a statement.
According to initial reports, the attack did not cause any injuries among civilians or refinery staff, he added.
Ukraine, itself targeted for the past four years by near-daily Russian bombardments, has been carrying out retaliatory strikes on oil refineries and Russian port and energy infrastructure.
