President Petro Poroshenko of Ukraine has vowed to destroy pro-Russian rebels who killed 23 servicemen in a rocket attack. Almost another 100 were injured when separatists fired Grad rockets on a border post in the Luhansk region.

“All who used ‘GRAD’ missiles against Ukrainian armed forces will be found and destroyed. For every life among our servicemen rebels will pay with tens and hundreds of their lives. None of the terrorists will avoid responsibility,” said Andriy Lysenko, spokesman for the Ukrainian Security and Defence Council, referring to the attack.

Despite the heavy losses, the Ukrainian army has been advancing on the cities of Donetsk and Luhansk which remain under rebel control.

Rebels blew up a bridge on the way to Horlivka, one of the towns they still control, to try to halt the army’s advance.

Separatists are buoyed by the Ukrainian losses, which the military said happened as troops tried to secure the porous border with Russia.

“The opposite side suffered significant casualties and damage. Fighting is happening all along the border which we control. We are confident of victory and that we’ll manage to keep the front-line,” said Alexander Borodai, Prime Minister of the self-proclaimed Donetsk People’s Republic:

Donetsk is tense: residents are taking shelter amid more reports of gunfire and explosions.

No more is there talk of a ceasefire; the latest attacks have raised the rhetoric as both sides dig in, promising victory.