Ukraine proposed a road map on Wednesday to solve the bloody conflict in the country’s east, while the United States and Kiev said there was evidence the Russian military was moving toward south-eastern Ukraine.
New reports of unabated fighting came from the city of Novoazovsk, more than 100 kilometres south of Donetsk, near the Russian border.
Kiev accused Moscow of opening a new front from Russian territory.
Local media reported that Novoazovsk was being shelled by Russian-made Grad missiles.
The violence came one day after a meeting between President Petro Poroshenko and Russian President Vladimir Putin in Minsk to seek an end to the violence.
Mr. Poroshenko’s road map would require re-establishing government control over the border with Russia, a bilateral ceasefire and the release of prisoners, according to Valeriy Chaly, a senior aide to Mr. Poroshenko.
Mr. Poroshenko and Mr. Putin had agreed to revive the so-called contact group, which consists of Russia, Ukraine and the Organization of Security and Co-operation in Europe (OSCE).
The United States accused Moscow of sending soldiers into Ukraine without telling them or their families where they are going.
The U.S. is “concerned” by the Russian government’s denials “even as its soldiers are found 30 miles (50 kilometres) inside Ukraine”, State Department spokeswoman Jen Psaki said.
She said dead Russian solders were being returned to Russia for burial.
The shifting Russian focus farther south along the eastern Ukraine-Russia border raised the spectre among some analysts that Moscow intends to invade near Mariupol to secure a land bridge to Crimea, which it seized earlier this year.
Responding to a reporter’s question about that possibility, Ms. Psaki confirmed the geography would be “correct” for a land bridge but declined to speculate on the motivation.
She called the shelling of residential areas between the border and Mariupol “incursions (that) indicate a Russian-directed counteroffensive is likely underway.” Ms. Psaki cited reports of columns of Russian tanks, multiple rocket launchers and armoured vehicles “pushing towards communities in south-eastern Ukraine”. European Union Energy Commissioner Guenther Oettinger, who took part in Tuesday’s talks, said he will meet Russian Energy Minister Alexander Novak on Friday to prepare the talks.
German Chancellor Angela Merkel, who played a key role in facilitating the talks, said that the dialogue must continue.
Both sides need to reach a ceasefire and a deal on border control, Ms. Merkel told Mr. Poroshenko in a telephone conversation, according to her spokesman, Steffen Seibert.
Ms. Merkel later spoke with Mr. Putin over the phone, and both agreed that the international efforts to solve the conflict must continue, the Kremlin said. Mr. Putin told Ms. Merkel that Russia would send new deliveries of humanitarian aid to eastern Ukraine.
Russian Foreign Minister Sergei Lavrov said that a second aid convoy, due to start this week, will not be the last, because the affected regions need massive help, according to Russian news agencies.
Russia was harshly criticized by the West when it sent more than 200 lorries with humanitarian aid last week to the embattled city of Luhansk without Ukrainian consent.
Ukrainian officials said on Wednesday that they had not been notified about a new Russian aid convoy.
Ukrainian Prime Minister Arseniy Yatsenyuk called for fresh talks in the so-called Geneva format — which would comprise the United States, Russia, Ukraine and the EU.
The pro-Russian separatists in eastern Ukraine claimed that almost 130 government troops had surrendered in the district of Starobeshevo, south of the separatist stronghold of Donetsk.
Ukraine’s National Security and Defence Council confirmed that Starobeshevo had been taken by the rebels. Council spokesman Andriy Lysenko said dozens of civilians were killed when rebels opened fire on three towns in the area.
Mr. Lysenko said that 13 soldiers were killed and 36 injured in the last 24 hours.
The rebels had earlier claimed that they had expelled government troops from their last stronghold in the region, the Ilovaisk transport hub.
Mr. Lysenko said that fighting in Ilovaisk continued and the government troops had received reinforcements.
City authorities in Donetsk said that at least six people were killed by artillery shelling.
Ukraine has long accused Russia of sending regular troops to aid the separatists in the east. On Wednesday, the government published a video in which eight captured soldiers identified themselves as Russian paratroopers.
The government has said that it captured 10 Russian soldiers in a village more than 20 kilometres from the border with Russia.
Mr. Putin said on Tuesday that the soldiers had probably entered Ukraine by accident while on a border patrol.
