Ukraine’s president, Volodymyr Zelenskiy, was involved in a traffic accident in Kyiv, but he is not seriously hurt, his spokesperson said in a Facebook post early on Thursday. Serhii Nykyforov, who did not say when the accident occurred, said Zelenskiy’s car had collided with a private vehicle. “The president was examined by a doctor, no serious injuries were found,” he said, adding the accident would be investigated. Medics accompanying Zelenskiy gave the driver of the private car emergency aid and put him in an ambulance, he said.

In his nightly televised address, video of which was posted shortly after the accident, Zelenskiy said he had just returned from the area around Kharkiv, adding that “almost the entire region is de-occupied” after a lightning counteroffensive to dislodge Russian troops. “It was an unprecedented movement of our soldiers – the Ukrainians once again managed to do what many thought was impossible,” he said. After visiting the liberated city of Izium, Zelenskiy said Ukraine’s troops had recaptured around 8,000 sq km (3,100 square miles) of territory.

Ukraine’s defence ministry found what its officials believe to be a “torture chamber” used by Russian troops to hold Ukrainian prisoners in the city of Balakliia. While some Balakliia residents told the Guardian that they had little interaction with the Russian forces, who mostly stayed on edges of the town, and did not experience the scenes of torture and execution seen elsewhere in the country, Serhiy Bolvinov, head of the Kharkiv region national police investigation department, said that 40 people had been detained during the occupation. One resident told the BBC that he was held by Russians in the city’s police station for more than 40 days and was tortured with electrocution.