Four buses carrying evacuees from Mariupol have left the besieged and destroyed port metropolis wherein Ukrainian forces are combating to preserve control, the authorities said Thursday.

“Four evacuation buses managed to leave the city the day before today through the humanitarian hall,” Deputy Prime Minister Iryna Vereshchuk said on social media, including that evacuations of women, kids, and the aged would preserve Thursday.

“The security situation is difficult. Things may change,” she added.

The battle for Mariupol appears to be nearing a tipping point after nearly two months of devastating fighting that has seen untold numbers of civilians trapped and killed.

Control of Mariupol and the separatist-controlled eastern Donbas vicinity might permit Moscow to complete a southern hall to the Crimean peninsula that it annexed in 2014, depriving Ukraine of tons of its coastline.

On Wednesday, senior Ukraine negotiator and presidential aide Mykhaylo Podolyak proposed a “special round” of negotiations in the city to “save our guys”.