KIEV/MOSCOW: Ukrainians and Russians were engaged in heavy fighting outside the eastern city of Donetsk, with both sides reporting casualties on Thursday.
Troops loyal to Moscow are trying to drive the Ukrainian military out of their positions in the suburbs, according to military reports from both countries.
The city of Donetsk itself has been controlled by pro-Russian separatists since 2014, but the Ukrainian army continues to hold large parts of the surrounding region of the same name.
Russian forces say they are making gains in the Donetsk region, although Kiev claims to have repelled their advance.
Russian Defence Ministry spokesperson Igor Konashenkov said that due to heavy losses, several Ukrainian brigades have withdrawn from their positions near Soledar, Avdiivka and Bakhmut.
The Ukrainian general staff said the situation in those three places was normal. "The enemy was unsuccessful in all the sections mentioned and retreated," the generals asserted.
If places like Bakhmut were to fall to Russian forces, this would open the way for Russian troops to the outskirts of the twin cities Sloviansk and Kramatorsk. More than half a million people lived in this area before the war.
On Wednesday night, fighting reportedly took place around the village of Pisky, which lies to the west of the former Donetsk airport.
At the same time, Russia continued its missile attacks on major Ukrainian cities in other regions. Four missiles hit Kharkiv in the north during the night. In the south, the regional centre of Mykolaiv was once again the target of Russian attacks. According to preliminary information, several residential buildings were damaged, but there were no deaths or injuries.
Meanwhile, less than a week after the devastating attack on a prisoner-of-war camp in eastern Ukraine, UN Secretary General António Guterres has announced an investigation late on Wednesday.
The United Nations had received a request to that effect from both Russia and Ukraine, Guterres said in New York. He was not authorised to launch criminal investigations, but could initiate a fact-finding mission, the UN chief said. Preparations were under way.
Dozens of Ukrainian prisoners of war were killed in the attack on the prison camp in Olenivka, near the city of Donetsk. The prison barracks were hit by a rocket on Friday night, according to Russian sources.
The Russian Defence Ministry later published the names of 50 prisoners killed and more than 70 injured. Moscow and Kiev blame each other for the attack.
Kremlin spokesperson Dmitry Peskov said on Thursday that it was"absolutely proven" that Ukraine had killed its own soldiers who were being held as prisoners of war. "There is evidence of this and nothing can be hidden here." -- dpa