and security personnel. May 1 May Pro-Russian militants seize the regional prosecutor's office in the eastern Ukrainian city of Donetsk. The People's Republic of China and Russia announce plans to hold joint naval exercises in the East China Sea in late May amid regional tensions about islands and airspace. 2 May – The Armed Forces of Ukraine launch a military operation against separatists in the city of Sloviansk with claims of many deaths and two Ukrainian Army helicopters downed. In the port city of Odessa, violent clashes kill at least 42 people, as pro-Ukrainians set the pro-Russian headquarters on fire. 4 May – Pro-Russian activists attack the police headquarters in Odessa, forcing the release of several people held over deadly violence two days before. 5 May – Russian media reveals that President Vladimir Putin secretly signed a decree (No. 279) honoring more than 300 journalists for their "objective coverage" of Crimea's seizure from Ukraine. 6 May Russian foreign minister Sergei Lavrov rules out any fresh talks in Geneva to defuse the crisis unless pro-Russian groups are also involved. Russian President Vladimir Putin signs into law a bill that bans profanity at arts, cultural and entertainment events. 7 May 2014 pro-Russian unrest in Ukraine: Pro-Russian militants recapture the city hall of the southern Ukrainian city of Mariupol hours after the Ukrainian government forces took control of the building from the militants. Five pro-Russian militants are killed and fifteen more are captured during clashes with the Ukrainian military in the outskirts of the southern city of Mariupol. Russian President Vladimir Putin says that Ukraine's presidential election on 25 May is a step "in the right direction", calling on anti-Kiev protesters to postpone an 11 May federalization referendum. Putin also added qualifying conditions. 8 May – Pro-Russian rebels push forward with plans for a referendum on 11 May ignoring Putin's statement to delay the vote. 9 May 2014 Crimea crisis: Russian President Vladimir Putin visits Crimea for the first time since the annexation, arriving in Sevastopol for Victory Day celebrations. Russia test fired several nuclear delivery systems on the Victory day celebrations and also sent a naval flotilla led by the Russian aircraft carrier Admiral Kuznetsov through the English Channel. 12 May – Pro-Russian insurgents in Donetsk and Luhansk declare the cities independent states whilst on choosing to join Russia after controversial hastily arranged referendums. 13 May – Another 13 individuals, including Russian