A Russian soldier has shot dead a Ukrainian naval officer in eastern Crimea, Ukraine's Defence Ministry said on Monday, in one of few fatalities reported since Russia took control of the Black Sea peninsula.
The ministry gave few details of the death late on Sunday in the town of Novofyodorovka. Russian forces took over Crimea in an almost bloodless operation before Moscow annexed the region last month.
This comes as Prime Minister Arseny Yatseniuk said on Monday that protests in eastern Ukraine in which pro-Russian activists seized public buildings in three cities are part of a plan to destabilize Ukraine and bring in Russian troops.
Saying Russian troops were within a 30 km (19 mile) zone from the Ukrainian border, Yatseniuk told a government meeting: "An anti-Ukrainian plan is being put into operation ... under which foreign troops will cross the border and seize the territory of the country.
Meanwhile, pro-Russia activists occupying regional offices in Donetsk, in eastern Ukraine, on Monday proclaimed the creation of a separatist Donetsk republic, a Reuters witness said.
One of the leaders of about 100 activists who moved into the building on Sunday night called for a referendum to be held no later than May 11 on the establishment of the "Donetsk people's republic".
Reading from a text, an unidentified, bearded man said protesters would call on Russia to send in a "peacekeeping contingent" in the event of aggressive action by what he described as the "illegitimate" authorities in Kiev.
Elsewhere, pro-Russian protesters who broke into state security headquarters in the eastern
Ukrainian city of Luhansk have seized weapons and road police have closed down entrances into the city, local police said on Monday.
Separately, Interior Minister Arsen Avakov said on his Facebook page that the regional administrative building in another eastern city, Kharkiv, had been cleared of "separatist" protesters.
Pro-Russian protesters also broke into a regional administrative building in the mining city of Donetsk on Sunday.
NATO
NATO does not see significant changes in the positioning of Russian troops close to Ukraine's eastern border, a NATO military official said on Monday, after pro-Russian protesters seized public buildings in three cities in eastern Ukraine.
"We do not see significant changes to Russian troop dispositions east of the Ukrainian border," the NATO military official said, when asked if the Western alliance had detected any movement by Russian forces near the Ukrainian border.
NATO officials estimate that Russia has around 40,000 troops close to Ukraine's eastern border.
Meanwhile, NATO said it would limit Russian diplomats' access to alliance headquarters in Brussels following its decision to suspend cooperation with Moscow because of Russia's annexation of Ukraine's Crimea region.
"The formerly extensive access to NATO headquarters will be denied to all representatives of the Russian Mission (to NATO), except the Russian ambassador, his deputy head of mission, and two support staff," NATO said in a statement.
"Should any other staff from the Russian mission require access for official business, standard visitor rules will apply. That means that the staff member will have to be announced, registered and escorted during their visits," it said.
US Ambassador to OSCE
The US ambassador to the OSCE said Russia had amassed tens of thousands of troops near the border with Ukraine and called on Moscow to take steps to de-escalate the situation.
"We have strong evidence that there are tens of thousands of forces on the border and again not in their normal peacetime positions or garrisons," Daniel Baer told reporters after an emergency meeting of the 57-member Organization for Security and Cooperation in Europe on Monday to discuss the issue.
The Russian delegation did not address the meeting, Baer and other diplomats said.
Russia
Russian Foreign Minister Sergei Lavrov told his German counterpart on Monday that "international assistance" was needed in Ukraine to help carry out constitutional reform, his ministry said in a statement.
Lavrov told Frank-Walter Steinmeier in a telephone conversation that it was necessary "to take urgent efforts to organize international assistance for the soonest start of a national dialogue of all political forces and regions of Ukraine ... in order to openly agree on a mutually acceptable constitutional reform."
IMF
German Finance Minister Wolfgang Schaeuble said on Monday he and his new French counterpart Michel Sapin would work to ensure that International Monetary Fund agreements with Ukraine are implemented as quickly as possible.
"We talked about how we agree completely that what the IMF is agreeing will be implemented as quickly as possible," Schaeuble said at a joint press conference with Sapin in Berlin.
Last week Ukraine said it hoped for $13 billion in external aid this year, including $7 billion from the IMF.
Schaeuble and Sapin are both due to travel to Washington later this week.
The German government is "very worried" about events at the weekend in eastern Ukraine, which included the seizure of state buildings by pro-Russian protesters, a spokesman said on Monday.
Pro-Russian demonstrators stormed regional government buildings in the industrial hub of Donetsk on Sunday as well as security service offices in nearby Luhansk and the regional administrative building in Kharkiv.
"The latest developments in Donetsk and in Kharkiv are something which we are all very worried about in the German government," said Chancellor Angela Merkel's spokesman Steffen Seibert.
"We must urgently renew our appeal to all those in positions of responsibility to help stabilize the region and avoid such escalation," he told a news conference.
REUTERS