Russia: A new dispute has broken out between Russia and Ukraine after Ukrainian officials seized control of a lighthouse near a Russian Crimean naval base.
Less than a fortnight after the two sides argued over gas imports, Kiev has taken control of the lighthouse used to guide Russian ships into the Black Sea base of Yalta.
Russia's Black Sea Fleet has been placed on alert and commanders ordered to negotiate the return of the lighthouse.
But Kiev insists that because the lighthouse is on Ukrainian territory, it has the right to take possession.
The lighthouse was occupied on Friday night by Ukrainian officials posing as a maintenance crew.
Russian soldiers blocked an attempt by Ukrainians to seize a second lighthouse further along the coast at Cape Sarych on Saturday. No shots were fired as soldiers prevented Ukrainian officials from entering the structure.
Moscow insists that part of a 1997 treaty allowing it to use Ukrainian naval bases for its ships includes control of lighthouses.
But Kiev says Russia is "illegally occupying" 35 of 100 beacons on its territory which belong to Ukraine, and says it has the right to take them back.
"You can't seize something that's yours," said Ukraine's foreign minister Boris Tarasyuk.
The row comes amid deteriorating relations between the two nations since Ukraine's new president Victor Yushchenko signalled he would loosen ties with Russia in favour of seeking links with Nato and the European Union last year.
On January 1st, Russia cut off gas supplies to Kiev, demanding a four-fold increase in price. That row ended when Kiev began siphoning off Russian gas destined for western Europe, and Moscow agreed to a two-fold increase and turned the taps back on.
However, Ukraine says it will make up the cash shortfall over rising gas prices partly by charging Russia the equivalent in rental for deep water bases on the Crimean peninsula.
These bases, at Sebastapol and Yalta, date from Soviet times, and have been leased by Russia for its navy until 2017.
If Ukraine takes control of the lighthouses and fog beacons for these ports, the Russian ships will be unable to safely enter and leave, in effect bottling up the fleet unless Russia agrees a rental increase.
The tension comes as German chancellor Angela Merkel makes her first visit to Moscow today. German support for Kiev was crucial in seeing Moscow back down in this month's gas dispute.