Russian President Vladimir Putin has paid a surprise visit to Mariupol, a Ukrainian port captured by Russia after its forces pounded much of it to ruins. An official video shows Putin driving a car through streets at night and speaking to people. The Kremlin said it happened late on Saturday. It is believed to be his first trip to a newly-occupied Ukrainian territory. Exiled Ukrainian city officials said Putin had visited at night so he would not see the destroyed city in daylight. The Kremlin said Putin’s decision to go to Mariupol had been “spontaneous”. The Russian leader is also reported to have met top military commanders in Rostov-on-Don, a Russian city just east of Mariupol. Tass news agency says he traveled to Mariupol by helicopter. In the video he is in the car with Russia’s Deputy Prime Minister Marat Khusnullin, who explains how the city is being rebuilt. Putin also appears to visit the Philharmonic Hall, which was used to stage trials of defenders of the Azovstal iron and steel plant, a huge industrial complex where Ukrainian troops held out before eventually surrendering. Mariupol has been under Russian occupation for more than 10 months after being devastated in one of the longest and bloodiest battles of the conflict. Ukraine says more than 20,000 people were killed there. UN analysis estimates that 90% of the buildings were damaged and around 350,000 people were forced to leave, out of a pre-war population of about 500,000. A group of locals have told the BBC that Russia is conducting an expensive campaign to rebuild the city and win over the hearts and minds of its people. The purpose is to assimilate Mariupol and make it Russia’s own. Russian authorities say 300,000 people are now living there. The fighting saw Russia strike a Mariupol theater where hundreds of civilians were sheltering. The building collapsed, and at least 300 are believed to have died there. Ukraine and human rights groups say the attack amounted to a war crime. It is among incidents for which Putin and his regime could be held legally responsible, the United Nations has said. The International Criminal Court said on Friday it had issued a warrant for the arrest of Putin over involving the illegal deportation of Ukrainian children to Russia. It means he could now be arrested if he sets foot in any of the court’s 123 member states. On Saturday Putin made an unannounced visit to Crimea, to mark the ninth anniversary of Russia’s annexation of the territory from Ukraine. He visited a new Russian arts school, a children’s summer camp and future cultural projects, such as the New Russia museum and museum of Christianity, Russian state media reported. The Kyiv authorities have vowed to liberate all Russian-occupied territories, including Crimea, which was annexed by Russia in 2014. — BBC