Children are seen with a cat at a temporary accommodation centre for evacuees in Bezimenne, Ukraine. Reuters

After nearly two months of siege, civilians holed up at a steel plant in the Ukrainian city of Mariupol began to be evacuated over the weekend, and people sheltering elsewhere in the city were to be allowed out on Monday, local officials said.

Video posted online Sunday by Ukrainian forces showed elderly women and mothers with small children climbing over a steep pile of debris out of the sprawling Azovstal steel plant’s rubble and eventually boarding a bus.

READ MORE

Russia strikes across southern, eastern Ukraine

US House Speaker Pelosi visits Kyiv, meets Ukraine president

More than 100 civilians were expected to arrive in the Ukrainian-controlled city of Zaporizhzhia on Monday, Ukrainian President Volodymyr Zelensky said Sunday.

"Today, for the first time in all the days of the war, this vitally needed (humanitarian) corridor has started working,” Zelensky said in a pre-recorded address published on his Telegram messaging channel.

A child sits on a packed bus during UN-led evacuations from the Azovstal steel plant in Mariupol, Ukraine. Reuters

Moreover, Ukrainian authorities are planning to evacuate more civilians from Mariupol on Monday, after dozens were finally brought to safety following weeks trapped under heavy fire in the strategic port city's Azovstal steel complex.

There were worries about the safety of evacuees. People fleeing Russian-occupied areas in the past have described their vehicles being fired on, and Ukrainian officials have repeatedly accused Russian forces of shelling agreed-upon evacuation routes.

The plant has endured a Russian blockade since Moscow's invasion on February 24, with stories of the harsh conditions in besieged Mariupol horrifying the world as a war which has seen thousands killed and millions displaced entered its third month.

Azovstal steel plant employee hugs her son as they meet at a temporary accommodation centre in Donetsk. Reuters

The UN said Sunday that a "safe passage operation" was taking place at the Azovstal steel plant. According to Kyiv, roughly 100 civilians have been evacuated from the besieged plant, while the International Committee of the Red Cross said it was "currently participating" in the operation.

Russia's defence ministry gave a lower figure of 80 civilians, adding: "Those who wished to leave for areas controlled by the Kyiv regime were handed over to UN and ICRC (Red Cross) representatives".

In his regular daily address to the nation, Ukrainian President Zelensky hailed the successful operation and said more evacuations were expected on Monday.

"For the first time, there were two days of real ceasefire on this territory. More than a hundred civilians have already been evacuated -- women and children first of all," he added.

Azov regiment members stand as civilians board a bus at the Azovstal steel plant in Mariupol, Ukraine. Reuters

The head of the Donetsk Regional Military Administration later said the evacuation would begin at 7am local time (0400 GMT).

One Russian news report put the number of civilians still in the plant at more than 500.

Moscow's defence ministry earlier confirmed that civilians were leaving, releasing a video that showed cars and buses travelling in the dark marked with a "Z", the letter used by the Russian forces in the conflict.