Russia stepped up its assault on eastern Ukraine on May 20, using artillery, rocket launchers, and aircraft to pound the regions of Donetsk and Luhansk, Ukrainian civilian and military officials said, as British intelligence predicted that Moscow’s offensive would intensify even further after securing Mariupol.

Local authorities in Luhansk said on May 20 that indiscriminate Russian bombardments killed at least 13 civilians over the past 24 hours and caused substantial damage.

Twelve people were killed in the town of Severodonetsk, where a Russian assault has been unsuccessful, the regional governor, Serhiy Hayday, said. Severodonetsk and the city of Lysychansk are in an area where Russian troops have launched an offensive.

In Donetsk, “the Russian enemy carried out massive artillery shelling of civilian infrastructure, including multiple-rocket launchers,” Ukraine’s General Staff said in a statement.

Ukraine’s Prosecutor-General’s Office said on May 20 that 232 children had been killed and 427 wounded since the beginning of the Russian invasion.

Ukrainian President Volodymyr Zelenskiy said Russia has “completely destroyed” Ukraine’s eastern Donbas region, accusing Russian forces of attempting to kill as many Ukrainians and do as much damage as possible.

“It is hell there — and that is not an exaggeration,” Zelenskiy said in his nightly address, repeating his accusation that Russia is committing genocide.

There are “constant strikes on the Odesa region, on the cities of central Ukraine. The Donbas is completely destroyed,” he said.

British military intelligence said early on May 20 that as many as 1,700 soldiers are likely to have surrendered at the Azovstal steel factory in Mariupol.

However, “an unknown number of Ukrainian forces remain inside the factory,” British intelligence said in its daily report issued by the Defense Ministry.

Moscow also said on May 19 that 1,730 Ukrainian fighters had surrendered from the steel factory. All of them, including those who were wounded, were reportedly transferred to territory in eastern Ukraine that is controlled by Russia-backed separatists