UK & World News
Russia Holds Ukrainian 'Terror Suspects'
Russia has detained 25 Ukrainians it suspects of planning terror attacks in the country, according to reports.
But the security service in Kiev has dismissed the claims as "nonsense".
The arrests come after an inquiry by the Ukrainian authorities indicated Moscow had a role in the deadly violence during anti-government protests in Kiev earlier this year, which left more than 100 dead.
It said Russian security staff had assisted the previous regime during the unrest.
The suggestion of involvement by the Kremlin was likely to further increase tensions between the neighbouring countries, after Russia seized control of the southern Crimea region.
Russia has denied any involvement in the unrest in Kiev.
Konstantin Dolgov, a Russian Foreign Ministry official, said: "We caution against forming hasty and politicised conclusions based on material and hypotheses that have 'suddenly' surfaced."
The detention of the group, which the Russian security service are calling "members of ultra-nationalist movements", will be widely seen as Moscow's response.
The investigation by the authorities in Kiev into the deaths of more than 100 protesters during unrest in February, concluded the killings were carried out by the feared Berkut riot police.
It also accused ousted President Viktor Yanukovych of being involved in drawing up the plans, which saw police snipers shoot dead dozens of demonstrators.
The deaths following three months of largely peaceful demonstrations over Mr Yanukovych's decision to seek closer ties with Russia rather than the EU, led the key Kremlin ally to flee.
His departure and installation of a new pro-Western government, paved the way for Moscow to seize control of the southern region of Crimea, which has a majority Russian-speaking population.
Airlines have now been warned to avoid the airspace over Crimea after Russia said it intended to take over air traffic control covering the peninsula.
The European Aviation Safety Agency (EASA) said there were "serious risks to the safety of international civil flights".
Earlier, Russia summoned the German ambassador to Moscow over remarks made by the country's finance minister.
Wolfgang Schaeuble said Russia's annexation of Ukraine's Crimea region were reminiscent of Adolf Hitler's aggression in 1938 that led to the annexation of German-speaking regions of Czechoslovakia.
In a statement, the Kremlin said: "We consider such pseudo-historical references by the German minister provocative.
"The comparisons by him are a gross manipulation of historic facts."
The stand-off over Crimea has caused the worst East-West crisis since the ending of the Cold War.
President Barack Obama has signed a law providing $1bn in loan guarantees to Ukraine, which also imposes sanctions on Russia.
Meanwhile, Russia has hiked gas prices by Ukraine by 80%, piling financial pressure on its neighbour and triggering criticism by the White House.
A Russian diplomat said the US needed to "calm down" and accept the annexation of Crimea.
Deputy Foreign Minister Sergei Ryabkov said: "What can one advise our US colleagues to do? Spend more time in the open, practice yoga, stick to food-combining diets, maybe watch some comedy sketch shows on TV."