Russia keeps pressure on Ukraine with Crimea stand-off

Russian and Ukrainian troops in Crimea are involved in a tense stand-off but fears of an imminent Russian assault have eased.
Ukraine's main military bases on the peninsula remain surrounded by Russian forces. Thousands of Russian troops have been pouring into Crimea.
An alleged ultimatum for Ukrainian forces to surrender - denied by Moscow - expired without incident.
Russia says its troops went in upon a request by the ousted president.

Viktor Yanukovych asked Russia to send troops across the border to protect civilians, Moscow's UN envoy Vitaly Churkin told the Security Council.

He said Mr Yanukovych had written to Russian President Vladimir Putin on Saturday.
Meanwhile, Russian troops who were on exercises in western Russia, near the Ukrainian border, have been ordered back to barracks after completing their tasks, the Kremlin says.
Up to 150,000 personnel were involved in the exercises, which started last week.
The BBC's Richard Galpin in Moscow says the exercises had fuelled fears that Russia was preparing its armed forces for a full invasion of Ukraine.
Ukraine's economy relies on Russian gas - and on Tuesday the head of Russia's gas monopoly Gazprom, Alexei Miller, said that from April Ukraine would no longer get discounted gas, because it had violated its agreements.
In Crimea, two Ukrainian warships are reported to be blocked by a Russian minesweeper in the port of Sevastopol.
The Ukrainian navy headquarters in the city was surrounded by pro-Russian gunmen and civilians, who formed a human chain.
And at Crimea's Belbek air base in Sevastopol, pro-Russian troops who have seized it fired warning shots into the air to prevent around 300 Ukrainian soldiers approaching, the Associated Press news agency reports.