Pro-Russian separatist rebels have been battling Ukrainian government troops in an arc cutting across Donetsk region, as far south as the Sea of Azov, reports GHN based on BBC.
The government-held coastal town of Novoazovsk came under shellfire, forcing people to shelter in basements.
A huge column of unidentified armour was reportedly sighted while rebels spoke of soldiers surrendering.
The fighting comes after Ukrainian President Petro Poroshenko promised a "roadmap" for peace in the east.
He was speaking in Belarus after holding his first direct talks on the crisis since June with Russian President Vladimir Putin.
Mr Putin said Russia, which denies supplying the rebels with weapons and covert forces, would assist a dialogue, but he insisted that stopping the fighting was a matter for Ukraine alone.
In other developments
• Mr Putin said agreement had been reached with Ukraine on further Russian humanitarian aid deliveries to east Ukraine
• Polish Prime Minister Donald Tusk said he had received Polish intelligence reports that regular units of the Russian army were operating inside Ukraine
• Ukrainian helicopter pilot Nadiya Savchenko appeared in court in the Russian city of Voronezh for a hearing on her continued detention in custody on charges of complicity in the killing of two Russian TV journalists