Russia said today it was reviewing "many requests" for protection from people in Ukraine in a move seen as upping the ante in the crisis over Crimea.
The statement from Moscow, coming on the eve of a hugely controversial Sunday referendum on Crimea's fate, indicates that Russia may deploy troops to elsewhere in Ukraine besides the Russian-speaking peninsula.
"Russia is receiving many requests to protect peaceful citizens" in Ukraine, the foreign ministry said in a statement. "These requests will be considered."
"Militants including from Pravy Sektor are continuing to behave in an outrageous manner," it said, referring to the radical Right Sector group whose members were at the forefront of last month's protests that ended in the ouster of pro-Kremlin president Viktor Yanukovych.
"We are getting alarming reports that a column with armed mercenaries from the Right Sector... Has left Kharkov for Donetsk and Lugansk," the ministry said, referring to Russian-speaking cities in eastern Ukraine.
The foreign ministry, claiming that a garment factory, apparently in Ukraine, was producing Russian military uniforms, hinted at possible action by provocateurs posing as Russian soldiers.
Two people were killed and several were injured in Kharkiv when nationalists opened fire on a group of men trying to storm their headquarters late on Friday.
The Kharkiv clashes came after a young man was killed in Donetsk during rallies.
Following the latest attack, the Russian foreign ministry urged Ukraine to outlaw nationalist groups.
Earlier this week Moscow said it reserved the right to protect its compatriots in Ukraine in case of attacks.
