Updated 6.28pm with Russian claim below - Top European Union officials on Thursday condemned Russia's bombing of a maternity hospital in the besieged Ukrainian city of Mariupol as a "war crime". 

"Mariupol is under siege. Russia's shelling of (a) maternity hospital is a heinous war crime," the bloc's foreign policy chief Josep Borrell wrote in a tweet. 

"Strikes of residential areas from the air and blocks of access of aid convoys by the Russian forces must immediately stop. Safe passage is needed, now," he added.  

European Commission head Ursula von der Leyen called the attack "inhumane, cruel and tragic".

"I am convinced that this can be a war crime. We need a full investigation," she tweeted.

The children's and maternity hospital in Mariupol was attacked on Wednesday in what Ukrainian President Volodymyr Zelensky described as a Russian "war crime", and which sparked global outrage.

Local officials said Thursday that at least three people were killed in the bombing, including a young girl. 

Video shared from the site by rescue workers showed a scene of complete devastation, with the wounded being evacuated, some on stretchers, past charred and burning cars and a massive crater by the building.

Russia's foreign ministry did not deny the attack but accused Ukrainian "nationalist battalions" of using the hospital to set up firing positions after moving out staff and patients.

Russia says Mariupol hospital attack 'staged' by Ukraine   

Meanwhile, the Russian army claimed Thursday that the attack on the children's hospital was a "staged provocation" by Ukraine. 

"The Russian aviation carried out absolutely no missions to hit targets on the ground in the Mariupol area," Russian defence ministry spokesman Igor Konashenkov said. 

"The airstrike that allegedly took place is a completely staged provocation to maintain anti-Russian hype for a Western audience," he said.