According to Ukrainian authorities, Russian "occupiers" have made it into all parts of the port city of Kherson. They were "very dangerous," Ukraine said. "We have no Ukrainian armed forces in the city, only peaceful residents who want to live here!" Kherson's mayor Igor Kolychayev said in a statement on Thursday night. Russian soldiers were in the city administration, but the Ukrainian flag was still flying over the building. Local resident Alexey Sandakov, who lives near downtown Kherson, confirmed on Thursday that the Ukrainian administration was still up and running. He told DW over the phone that he hadn't been onto the street in two days. "We nailed the windows and doors shut," he said, explaining they'd set up a camera to show them what was going on on the street outside. "We saw military vehicles, but no ground forces." Sandakov and another resident, Artemii Perun, also reported looting by Russian soldiers. Perun said he had temporarily moved to another part of the city because his apartment on the outskirts was within range of the fighting. He was still hearing shots on Thursday night. Reports by the Ukrainian army, however, no longer mention any fighting for the city. The port city of Kherson in southern Ukraine is strategically important for Russia, being close to the Crimean Peninsula and at the mouth of the Dnipro River. With a population of around 300,000, it would be the first major city to be taken by Moscow's troops. According to Artemii Perun, Russian troops have set up roadblocks. "Anyone who is traveling alone or as a couple and has food or medicine with them can usually pass. But there are also some who have been turned away." There are long queues outside grocery stores and pharmacies, he says. "Many try to help each other and exchange medicines with each other." Most residents, however, stay at home if possible. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video US pensioner Donald Flett has been living in Kherson for years. He reported over the phone that shortly before the Russian invasion, he saw missile attacks near his home on the northern outskirts of the city. He sent DW a video that is supposed to show hits on the residential area. "A missile hit the first floor of a block of flats. An old woman lived there. They carried her out in pieces," he says. He also confirmed that there has been no change in the city administration so far. He is in contact with Mayor Kolychayev, who is currently negotiating a humanitarian corridor with the Russian army. Moscow began its invasion of Ukraine a week ago and has since attacked several cities. Over the past days, Russia has stepped up its airstrikes — while at the same time, talks have taken place between Moscow and Kyiv. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video The much smaller port city of Berdyansk, 350 kilometers east of Kherson, has already been occupied by Russian troops. An offensive is also underway against the port city of Mariupol, a little further to the east. "Today was the most difficult and cruel day of the war so far," Mariupol mayor Vadim Boichenko said in a video message. The city council said Russia kept Mariupol under constant fire and was deliberately damaging civilian infrastructure. Destroyed bridges and railroad tracks made evacuations and delivery of supplies impossible. Water supply, energy and heating were also all affected. According to the mayor of the southern Ukrainian city of Enerhodar, Russian troops fired on a checkpoint set up by civilians there. The enemy had advanced with a large military convoy and had used weapons against citizens, Dmytro Orlov said on Thursday. These claims could however not initially be verified. Russia strongly denies targeting civilians. This article was originally written in German