Ukraine's President Volodymyr Zelensky called on Saturday for the evacuation of the eastern Donetsk region which has seen fierce clashes between his country's forces and the Russian military.

The governor of the eastern Donetsk region, where Moscow is focusing the brunt of its offensive, said that six civilians were killed and 15 wounded by strikes on Friday.

"There's already a governmental decision about obligatory evacuation from Donetsk region," he said in his daily address. "Please, follow evacuation. At this phase of the war, terror is a main weapon of Russia."

Zelensky warned that thousands of people, including children, were still in the battleground areas of the Donetsk region.

"The decision to leave should be taken at some point. The more people who leave Donetsk region now, the fewer people the Russian army will kill," he said.

Logistics and support operations were being handled by the authorities "from A to Z", he added.

"We will help you. We are not Russia. We will do everything possible to save the maximum number of human lives and to maximally limit Russian terror." 

Ukraine condemns Russian call to 'hang' Azov fighters

Ukrainian officials on Saturday denounced a call by Russia's embassy in Britain for fighters from the Azov regiment to face a "humiliating" execution.

The Russian tweet came as Moscow and Kyiv traded blame over a strike on a jail holding Ukrainian prisoners of war in Russian-controlled territory that killed around 50 people, reportedly including members of the Azov regiment.  

"Azov militants deserve execution, but death not by firing squad but by hanging, because they're not real soldiers. They deserve a humiliating death," Moscow's diplomatic mission wrote in an overnight Tweet. 

The post -- which Twitter said violated its rules on "hateful conduct" -- was accompanied by a video purportedly showing a couple in Russian-held Mariupol claiming they had been shelled by Ukrainian forces at the Azovstal metal plant during the fierce battle for the city. 

"Russia is a terrorist state. In the 21st century, only savages and terrorists can talk at the diplomatic level about the fact that people deserve to be executed by hanging. Russia is a state sponsor of terrorism," Andriy Yermak, head of the office of the Ukrainian presidency, wrote on Telegram. 

"What more evidence is needed?"

Russia and Ukraine have accused each other of carrying out the deadly bombardment of the jail holding captured servicemen in Kremlin-controlled Olenivka. 

Moscow said Ukraine targeted the facility in a bid to dissuade its troops from surrendering, while Kyiv accused Russia of carrying out a "war crime" by striking the prison.  

Ukraine's foreign ministry spokesman Oleg Nikolenko tweeted "there is no difference between Russian diplomats calling for execution of Ukrainian prisoners of war and Russian troops doing it in Olenivka. They are all accomplices in these war crimes and must be held accountable."

Ukrainian forces, including members of Azov, in May ended a weeks-long siege of the vast Azovstal plant in Mariupol by agreeing to surrender. 

Around 2,500 combatants were taken captive by Moscow's forces after calling a halt to their resistance.

Azov regiment commander Mykyta Nadtochiy said in a video address: "We consider the attack on Olenivka an act of public execution committed by Russia with complete impunity." 

Those responsible for this act will be "found wherever they are" and Ukraine as a state "will ensure that they are punished justly," he added.

The Azov regiment is a former volunteer battalion that has drawn controversy for its links to far-right figures.  

The group was formally incorporated into Ukraine's National Guard in 2014 as it helped fight Kremlin-backed separatists in east Ukraine. 

Azov fighters are a hate figure for Russia's tightly-controlled state media and officials, who demonise them as "neo-nazis". 

The Kremlin claims it launched its invasion of its pro-Western neighbour in February in part due to the need to "denazify" the country.

Kyiv and its Western allies have roundly rejected the claim and say it was used as a pretext to fuel support inside Russia for the assault on Ukraine.  

Russia slams 'outrageous' comments by Norwegian consul

Russia's foreign ministry Saturday denounced the "outrageous" behaviour of a Norwegian consul in Russia, after security footage of her insulting Russians at a hotel reception was shared on social media.

In the video, posted on a Telegram channel reputed to be close to the Russian security services on Saturday, a woman introduced as Elisabeth Ellingsen, Norwegian consul in the Arctic city of Murmansk, appears exasperated as she waits for a clean room.

"I hate Russians... Just give me a room... I'm used to clean rooms, I'm from Scandinavia," she says in the edited version of the footage on the Mash channel.

On Saturday afternoon, the video had been viewed more than 500,000 times.

Russian diplomatic spokesperson Maria Zakharova said on Telegram: "The Russian foreign ministry is considering a reaction to this outrageous act of hatred, nationalism and xenophobia." 

The Norwegian foreign ministry said it "deeply regretted" the incident. 

"The sentiments expressed do not reflect Norwegian policy or the Norwegian attitude towards Russia and the Russian people," it assured AFP, adding that the ministry was dealing with the incident "through the appropriate channels".

According to the website of the Norwegian embassy in Moscow, the Norwegian Consulate General in Murmansk has been temporarily closed since July 1, due to the "difficult" situation in bilateral relations.

The Norwegian foreign ministry did not specify whether the incident took place before or after the temporary closure of the consulate.

The diplomatic incident comes at a time of great tension in relations between Russia and the West over Russia's offensive in Ukraine, which has prompted a volley of European and US sanctions against Moscow.