Ukrainian President Volodymyr Zelenskiy said on Monday that more than 3,000 North Korean soldiers have been killed and wounded in Russia's Kursk region and warned that Pyongyang could send more personnel and equipment for Moscow's army.

At least five people, including a 9-year-old child, were killed in the attack, which took place in the eastern city of Magdeburg. The authorities are still seeking a motive.

There were mounting questions on Sunday about whether the deadly attack on a German Christmas market could have been prevented after it emerged that various authorities across the country had received warnings and tip-offs about the perpetrator.