The pro-Russian separatists in eastern Ukraine are preparing intensively for the referendum on independence, which is planned to be held tomorrow. At the same time, Ukrainian security forces continue their operations after the deadly clashes which occurred on Friday in Mariupol.

This city of southeast Ukraine has been the backdrop of fierce fighting, including an attack on the headquarters of the local police launched by group of about 60 people, armed with automatic weapons. In the following battle, 20 of the attackers and a police officer were killed, according to Interior Minister of Ukraine Arsen Avakov. Among them, a journalist who was murdered in cold blood by a Ukrainian soldier.

The separatists in the region decided to proceed with a referendum, despite Putin’s request for its postponement.

The Russian president angered both Kiev and the West on Friday, when he visited Crimea, for the first time after the annexation of the peninsula by Russia in March. In Sevastopol, the port where the Russian fleet in the Black Sea is docked, Putin attended the celebrations marking the victory of USSR over Nazi Germany in 1945.

In Ukraine, celebrations were limited. Prime Minister Arseniy Yatsenyuk attended a solemn ceremony in a park in Kiev. “69 years ago we fought together with Russia against fascism (…) Today Russia is waging war against Ukraine,” Ukrainian Prime Minister said in his speech.

In a telephone conversation he had on Friday with the head of American diplomacy John Kerry, Russian Foreign Minister Sergey Lavrov asked him to pressure Ukrainian authorities to stop the “military operations” in southeastern Ukraine.

On Thursday, however, the government in Kiev reiterated that it will not, under any circumstances, abandon the effort to restore order to the Russian-speaking provinces.