KIEV, Ukraine (AP) - Pro-Russian forces seized three Ukrainian warships Thursday and Ukraine said its troops were being threatened in Crimea as the U.S. announced a new round of sanctions against Russia for its annexation of the Black Sea peninsula.
Tensions in the region remained high despite the release of a Ukrainian naval commander held by pro-Russian forces.
Shots were fired but there were no casualties as the Ukrainian corvette Khmelnitsky was seized in Sevastopol, according to an AP photographer at the scene. Another ship, the Lutsk, was also surrounded by pro-Russian forces. An AP photographer later saw Ukrainian servicemen disembarking a third ship, the Ternopil corvette.
A child pulls a toy truck past pro-Russian soldiers standing outside a Ukrainian military base in Perevalne, Crimea, Thursday.
The Defense Ministry had no immediate information on the incidents.
Ukrainian Deputy Defense Minister Leonid Polyakov accused Russian troops of constantly threatening to storm military bases where Ukrainian soldiers were located, according to the Interfax news agency.
In Geneva, Ukraine's ambassador to the United Nations warned of a sharp deterioration in relations between the two neighbors, saying that Russia appears to be preparing for a military "invasion" in more areas of his country.
Ambassador Yuri Klymenko said there were "indications that Russia is on its way to unleash a full-blown military invention in Ukraine's east and south" since its annexation of Crimea. He said his statement was based on information from non-governmental organizations.
President Barack Obama on Thursday expanded U.S. economic sanctions against Moscow, targeting President Vladimir Putin's chief of staff and 19 other individuals as well as a Russian bank that provides them support. Obama also warned of more costs to come for the Kremlin if the situation worsens, saying he also had signed an executive order that would allow the U.S. to penalize key sectors of the Russian economy.
Within minutes of Obama's speech, Russia retaliated by banning entry to nine U.S. officials and lawmakers.
Speaking after meeting with Putin in Moscow, U.N. Secretary-General Ban Ki-moon said he "emphasized that all parties refrain from any hasty or provocative actions that could further exacerbate an already very tense and very volatile situation."
In an address to the German Parliament in Berlin, Chancellor Angela Merkel said the EU was readying further sanctions and that the G-8 forum of leading economies had been suspended indefinitely. Russia holds the presidency of the G-8 and President Vladimir Putin was due to host his counterparts, including President Barack Obama, at a G-8 summit in Sochi in June.
"So long as there aren't the political circumstances, like now, for an important format like the G-8, then there is no G-8," Merkel said. "Neither the summit, nor the format."
The U.S. and the EU have slapped sanctions on individuals involved in what they say was Crimea's unlawful referendum over joining Russia. Moscow formally annexed Crimea earlier this week in the wake of the poll. The Black Sea peninsula had been part of Russia for centuries until 1954 when Soviet leader Nikita Khrushchev transferred it to Ukraine, and many residents were happy about rejoining Russia.