The evacuation was announced by Ukrainian Deputy Defence Minister Hanna Maliar, Polish state news agency PAP reported.
Evacuation from Mariupol
In a video statement on Monday evening, Maliar said: "On 16 May, 53 badly wounded people from Azovstal [steel works] were evacuated to a medical facility in Novoazovsk to be given medical assistance."
She added: "Another 211 people were taken to Olenivka via a humanitarian corridor."
Both these cities are in the eastern Donbas region and remain under the control of Russian-backed separatists, news outlets reported.
"For their future return home, an exchange procedure will be carried out," Maliar told the nation, adding that the Mariupol defenders would be exchanged for captured Russian soldiers.
Maliar paid tribute to the troops who had held out for 82 days in Mariupol’s Azovstal steelworks, saying that thanks to them, Ukraine had gained “crucial time,” and their mission was now complete.
She said the authorities were working to rescue those remaining at the steel mill.
‘Ukraine needs its heroes alive’: Zelensky
Meanwhile, Ukraine’s President Volodymyr Zelensky mentioned the evacuation in his nightly video address, telling Ukrainians: “Thanks to the actions of the Ukrainian military - the Armed Forces of Ukraine, intelligence, the negotiating team, the International Committee of the Red Cross and the United Nations, we hope that we will be able to save the lives of our guys."
He added: "Among them are the seriously wounded. They are being provided with medical aid."
"I want to emphasise: Ukraine needs Ukrainian heroes alive," Zelensky said.
The defence of Mariupol
It is estimated that some 600 troops had been defending the Azovstal steel plant, the last Ukrainian stronghold in the strategic southern port of Mariupol. It gave Kyiv’s forces elsewhere valuable time to prepare for the Russian attack, according to news outlets.
Mariupol itself has been almost completely destroyed by Russian bombardment, with civilian casualties estimated at well into the thousands, the PAP news agency reported.
Tuesday is day 83 of Russia’s invasion of Ukraine.
Source: PAP, Reuters, bbc.com