UKRAINE’S anti-fascist forces launched an offensive against the city of Mariupol at the weekend, with separatist leaders saying they had lost all faith that Kiev would stick to the ceasefire signed last autumn in Minsk.

Heavy rocket fire slammed into the eastern parts of the city on Saturday as the self-declared Donetsk People’s Republic vowed to drive the Ukrainian army out of the Donbass region.

City authorities said at least 30 people died when shells hit a market, schools and homes. Ukrainian military chiefs rushed extra troops to the area as President Petro Poroshenko denounced the attack as “terrorism.”

A UN security council motion to condemn the assault was vetoed by Russia, which pointed out that the US, Britain and France had blocked any criticism of the Ukrainian government’s offensives.

Separatist spokesman Denis Pushilin said there was no point in trying to stick to a ceasefire which Kiev’s constant attacks on Donetsk had undermined.

“Poroshenko is cynical beyond all limits,” he told Interfax. “For us the Minsk process was a question of life for our civilians — for him, a cover.”

But US President Barack Obama continued to blame Moscow alone for the bloody civil war engulfing eastern Ukraine.

Washington was “deeply concerned” by the “aggression that these separatists with Russian backing, Russian equipment, Russian financing, Russian training and Russian troops are conducting,” he declared.

Kiev and the West have repeatedly accused Russia of sending troops into Ukraine, although Moscow has challenged them to produce evidence.

Ukrainian Interior Minister Arsen Avakov said that the country was now handing heavier weapons to the notorious Azov battalion, a regiment composed of neonazi paramilitaries, so it could take the lead in the fight for Mariupol.

Battalion commander Andriy Biletsky has declared his goal as “to lead the white races of the world in the final crusade for their survival, a crusade against semite-led subhumanity.”

The battalion has repeatedly been accused of murdering civilians and boasts of having recruited white supremacists from around the world to join its ranks.