Pro-Russia rebels and Ukrainian authorities have agreed on a humanitarian corridor to evacuate civilians from the epicentre of fighting in eastern Ukraine as German and French leaders prepare to take a peace plan to Moscow.

A group of eight European military observers detained by pro-Russia insurgents in Ukraine has appeared in public and given assurances that they are not being mistreated.

Russia’s foreign minister has promised a firm response if its citizens or interests come under attack in Ukraine – a vow that came after Ukraine announced a renewal of its “anti-terror” campaign against those occupying buildings in its troubled east.

Pro-Russia demonstrators who seized the regional administration building in Ukraine’s second-largest city have been driven out of the building and about 70 of them were arrested, Ukraine’s interior minister said today.