The Guardian (U.K.) is reporting Ukraine has invaded Russia. Supposedly Ukrainian troops are something like nine miles inside the Russian border, and near an important node on a pipeline by which Russia ships natural gas and earns plenty thereby.
It is claimed they crossed into a thinly defended border region from northern Ukraine. By doing this they will make Russia defend its entire border with Ukraine, which will tie down a lot of troops who are then not available to fight on the front lines in eastern Ukraine.
Reuters has the same story, with similar details. Making the Russian invasion as uncomfortable for Russia as possible seems logical Ukraine tactics.
Later … UnHerd reports this incursion and calls the region where it occurred “Kursk.” This treatment views the raid as having primarily propaganda value.