Russian President Vladimir Putin on Thursday ordered his troops to block, instead of storming, Mariupol’s Azovstal steel plant, which remains the last Ukrainian stronghold in the city, the Associated Press reported.

His orders came after Russian Defence Minister Sergei Shoigu told Putin that Moscow had taken control of the port city in southeastern Ukraine.

“Mariupol has been liberated,” Shoigu told Putin in a televised meeting, AFP reported earlier on Thursday. “The remaining nationalist formations took refuge in the industrial zone of the Azovstal plant.”

The Russian troops had largely besieged the port city of Mariupol since the early days of the conflict that began in February this year. However, Ukrainian forces defended it for a long time.

Shoigu said that about 2,000 Ukrainian troops were in the giant steel plant, which has a network of underground tunnels and bunkers spanning an area of about 11 square kilometres, AP reported. Meanwhile, Ukrainian President Volodymyr Zelenskyy said that nearly 1,000 civilians were also trapped at the site.

Earlier, Putin described the “liberation of Mariupol” as a “success for Russian forces”.

“There is no need to climb into these catacombs and crawl underground through these industrial facilities,” Putin told the Defence Minister, reported AFP. “Block off this industrial area so that not even a fly can escape.”

Russian forces were now aiming to capture Donbas, the eastern industrial heartland of Ukraine, according to AP.