An anti-fascist activist kidnapped by Ukraine’s security forces was released from state captivity yesterday.

Maria Matyushenko’s arrest on Tuesday night came as Kiev secret services SBU carried out a series of illegal raids on Marxist organisation Borotba (Struggle) — of which she is a member — offices and members across Ukraine.

Fascist coup-installed President Petro Poroshenko also warned late on Tuesday that he may prematurely cancel a barely holding ceasefire with anti-Kiev rebels in the east after they shot down a military helicopter, killing nine.

SBU bootboys — who are waging a war on left-wing forces that opposed the fascist putsch that grew out of the Euromaidan protests — burst into Ms Matyushenko’s flat in Dnepropetrovsk, south central Ukraine.

They ransacked her home, seizing mobile phones and computers, including an iPad belonging to her 13-year-old sister.

Armed paramilitaries had also tried to arrest Borotba activists following a regular anti-fascist rally in Kharkov last month.

Anti-fascists said state authorities had launched a crackdown on social media accompanied by “mass interrogations” of activists carried out jointly by security services and far-right militants.

But while the neonazi juggernaut rolled on, its Western backers gave a cool reception to Russian President Vladimir Putin’s moves to ease tensions in the east, where armed anti-Kiev militants have seized control in favour of closer ties with Moscow.

The Duma cancelled a resolution yesterday that gave Russia the right to use military force in Ukraine in a bid to avoid further sanctions from the Western powers that stoked the crisis.

But German Chancellor Angela Merkel told MPs that while the move was an “important psychological point,” in the face of slow progress towards peace the EU would still be prepared to increase sanctions.

The self-declared EU wunderkind said that more diplomatic failures would spark a third round of sanctions, imposing penalties on entire sections of the Russian economy rather than just individuals.

But the US seemed more willing to ratchet back the tension with its eastern rival.

Obama administration officials indicated that the positive moves were enough to delay sanctions that had been mooted for this week.