The United States accused Russia today of sending its agents to stoke a flaring secession crisis in eastern Ukraine that Moscow itself conceded could spill over into civil war.
The blunt US charge came as Ukraine's embattled leaders waged an uphill battle to keep their culturally splintered nation of 46 million together after the February ouster of a pro-Kremlin president and subsequent loss of Crimea to Russia.
An eery echo of the Black Sea peninsula's separation sounded on Sunday when militants -- many of them masked -- stormed a series of strategic buildings across a swathe of heavily Russified eastern regions and demanded that Moscow send its troops for support.
Ukraine mounted a counter-offensive today by vowing to treat the separatists as "terrorists" and making 70 arrests in a nighttime security sweep aimed at proving the Kremlin's involvement in the secessionist movement.
An urgent deployment of forces saw Kiev also regain control of an administration office in Kharkiv and the security service headquarters of Donetsk -- the stronghold of Viktor Yanukovych prior to his ouster as president and flight to Russia.
But Kalashnikov-wielding militants still held on to the main police building in the nearby city of Lugansk after breaking into its massive weapons cache and releasing several activists who had been accused of plotting a coup.
Ukraine's state security service said today it had "established" that the Lugansk militants had rigged its regional centre with explosives and were holding 60 people "against their will, not letting them leave the building and return home."
But the agency did not explain why it was making the announcement two days after the actual raid or say how it had gained information from inside the heavily-fortified building.
Hundreds of pro-Russians also remained holed up inside the Donetsk administration centre a day after proclaiming the creation of a sovereign "people's republic" and demanding that an independence referendum be held before May 11.
"We have formed a provisional government in Donetsk," separatist leader Vadym Chernyakov told AFP inside the occupied building.
