The United Nations and the International Criminal Court warned Russia Friday that attacks that target civilians were banned and could amount to war crimes, as it raised the use of cluster bombs in Ukraine and invading Russian forces ramp up bombardments of city infrastructure.
The International Criminal Court also voiced concern over attacks on innocent victims caught up in the conflict.
"If attacks are intentionally directed against the civilian population: that is a crime. If attacks are intentionally directed against civilian objects: that is a crime," ICC chief prosecutor Karim Khan said.
"I strongly urge parties to the conflict to avoid the use of heavy explosive weapons in populated areas," added Khan. "There is no legal justification, there is no excuse, for attacks which are indiscriminate, or which are disproportionate in their effects on the civilian population.”
The conflict Wednesday saw a maternity ward and a hospital hit in the surrounded southeastern city of Mariupol where a young girl was one of three people listed as killed in an attack which brought widespread condemnation.
The Hague-based ICC last week opened an investigation into the situation in Ukraine after 39 member states gave it the green light to do so.
Khan said Friday Japan and the Republic of North Macedonia had also called for the investigation. Ukraine is not a signatory to the Rome Statute treaty which established the ICC but it did in 2014 officially recognise the court's jurisdiction for crimes committed on its soil. Russia withdrew its signature from the Rome Statute in 2016.
The UN human rights office said Friday it was gravely concerned by the rising death toll in the conflict following Russia's full-scale invasion of Ukraine on February 24.
The Office of the UN High Commissioner for Human Rights (OHCHR) has recorded 564 civilians killed and 982 injured, though it acknowledged that the actual figures are "considerably higher."
"We remind the Russian authorities that directing attacks against civilians and civilian objects, as well as so-called area bombardment in towns and villages and other forms of indiscriminate attacks, are prohibited under international law and may amount to war crimes," OHCHR spokeswoman Elizabeth Throssell said.
"Civilians are being killed and maimed in what appear to be indiscriminate attacks, with Russian forces using explosive weapons with wide area effects in or near populated areas," she told reporters in Geneva.
She said these included missiles, heavy artillery shells, rockets and air strikes.
"We have also received credible reports of several cases of Russian forces using cluster munitions, including in populated areas."
Throssell said on February 24, a cluster munition exploded at the Central City Hospital in Vuhledar, in government-controlled Donetsk, killing four civilians and injuring 10 others. It also damaged ambulances, civilian vehicles and the hospital itself.
"There were other cluster munition attacks in several districts of Kharkiv, in which nine civilians were killed and 37 injured," she said. "Due to their wide area effects, the use of cluster munitions in populated areas is incompatible with the international humanitarian law principles governing the conduct of hostilities."
Russian strikes hit fresh civilian targets in central and eastern Ukraine Friday, including a city previously considered a safe haven, as Moscow's troops edged closer to the capital Kyiv.
More than two weeks after Russia invaded its neighbour, hundreds of thousands of civilians remain trapped and under bombardment, while the UN estimates some 2.5 million have fled.
The situation is particularly dire in the southern port city of Mariupol where local officials said Friday more than 1,500 people have been killed during 12 days of Russian siege.
Western powers have imposed unprecedented sanctions on Moscow and sent funds and military aid to Kyiv, but have failed to halt the advance, including against civilian targets.
US President Joe Biden said Friday that Washington and its allies would end normal trade relations with Russia and announced a ban on imports of Russian vodka, diamonds and seafood. The US will also ban the export of US luxury goods to Russia and Belarus.
Putin must pay the price. He cannot pursue a war that threatens the very foundation of international peace and stability and then ask for help from the international community," Biden said.
US and European stock markets had risen earlier, buoyed by Putin's comments about "certain positive shifts" in negotiations with Ukraine.
The first high-level talks between the two sides on Thursday failed to make a breakthrough, but Putin said negotiations are "now being held on an almost daily basis."
But there was no let up in the bombardment, with three missiles hitting civilian buildings in the central city of Dnipro early Friday, destroying a shoe factory and killing a security guard.
The industrial hub of one million inhabitants had been considered a relatively safe haven, a centre for coordination of humanitarian aid and those fleeing more severe fighting in the country's east.
But images of its charred or destroyed buildings – including a kindergarten with windows blown out – now join those from Kharkiv and Mariupol as testimony to the brutal conflict.
Elsewhere, a care home for disabled people was hit in the village of Oskil, near Kharkiv in eastern Ukraine, local officials said, although no casualties were reported.
Russia also announced the military airfields of Lutsk and Ivano-Frankivsk, in western Ukraine closer to the Polish border, had been "put out of action."
Ukraine claimed the widening of Russia's targets followed its failure to secure cities already under siege, and insisted Moscow had made no "significant progress" in the last 24 hours.
But the capital Kyiv risks being entirely surrounded, with presidential adviser Mykhailo Podolyak calling it a "city under siege."
He tweeted that it was "ready to fight", with checkpoints prepared and supply lines in place, adding: "Kyiv will stand until the end.”
The Ukrainian military warned on Thursday Russia was trying to "block" Kyiv by taking out defences to the west and north of the capital, adding that there was also a risk to Brovary in the east.
The northwest suburbs, including Irpin and Bucha, have already endured days of heavy bombardment but Russian armoured vehicles are also advancing on the northeastern edge.
Britain's Defence Ministry said Russian forces were committing more forces to encircle key cities, reducing numbers available to continue the advance.
The Kremlin on Friday announced that Syrian fighters can fight for Russia in Ukraine after Putin backed plans to draft in 16,000 volunteers, mostly from the Middle East.
Ukrainian President Volodymyr Zelensky accused Russia of hiring "murderers from Syria, a country where everything has been destroyed... like they are doing here to us".
In a video message recorded outside his presidential office in Kyiv, Zelensky also demanded the European Union "do more" to help his country.
Around 100,000 people have been able to leave the northeastern city of Sumy, the eastern city of Izyum, and areas northwest of Kyiv in the last two days, Ukrainian officials said.
But the president warned living conditions were deteriorating fast, in the northeast, around the capital and in the east.
"In the Sumy, Kyiv and Donetsk regions, there is no more electricity. Yes, there are problems with heating. There is no gas, no water," he said. "It's a humanitarian catastrophe."
In Mariupol, Mayor Vadym Boichenko said Russian warplanes had targeted residential areas in the city "every 30 minutes" on Thursday, "killing civilians, the elderly, women and children."
Zelensky accused Moscow of launching a "tank attack" targeting a humanitarian corridor to which he had dispatched a convoy to try to get food, water and medicine into the city.
On Wednesday, he and top Western officials also accused Russia of a "war crime" for the bombing of a children's hospital there that local officials said killed three people, including a young girl. Russia's Army claimed the bombing was a "staged provocation" by Ukraine.