The International Committee of the Red Cross (ICRC) is working with the United Nations in an ongoing operation to move people out of Mariupol and the besieged Azovstal steel plant, the ICRC said in a statement.
“The ICRC confirms that a safe passage operation is ongoing, in coordination with the UN and the parties to the conflict. The convoy to evacuate civilians started on 29 April, travelled some 230 kilometres and reached the plant in Mariupol on Saturday morning, local time, according to the statement. "The ICRC insists on the fact that no details can be shared until the situation allows, as it could seriously jeopardize the safety of the civilians and the convoy. Relevant local authorities are communicating with the civilians about practical details."
Ukrainian President Volodymyr Zelensky confirmed in a tweet on Sunday that the "Evacuation of civilians from Azovstal began."
"The 1st group of about 100 people is already heading to the controlled area," he added.
Mariupol's city council said Sunday there was a "chance" to evacuate civilians from the besieged city of Mariupol.
The Council urged people to gather at 4 p.m. local time (9 a.m. ET) near a shopping center called "Port City" in order to evacuate them to the southern region of Zaporizhzhia.
"If you have relatives or acquaintances in Mariupol, try to contact them by all ways. Call, text and say that it is possible to go to Zaporozhzhia, where it is safe," the Council said on Telegram.
"We pray that everything works," it added.
A local Telegram channel said earlier that through 3 p.m. local time, a "green corridor" would be open for citizens wishing to enter territory "controlled by the enemy in the Kamensky district."
There are about 100,000 people still in Mariupol, even though most of the city has been severely damaged by weeks of shelling and airstrikes by Russian forces.
Ukrainian officials have been giving more details on the evacuation of civilians who had been trapped at the Azovstal steep plant.
David Arakhamia, an advisor to President Zelensky, said: "Today is the third day of a special operation we call "Azovstal evacuation." Since the beginning of the war, since the beginning of the blockade of Azovstal, we have managed to withdraw more than 100 civilians - small children, women and the elderly."
Iryna Vereshchuk, deputy prime minister, said on Ukrainian television: "Sorry, we were silent. We really wanted everything to work out. Our silence was in order for people to come out alive and unharmed. More than 100 people have been evacuated, and the evacuation continues. All this happened thanks to the control of the President of Ukraine Zelensky, Antonio Guterres, and the International Committee of the Red Cross, for which we are very, very grateful."
Some more context: Mariupol is home to the Azovstal steel plant, which has been subjected to heavy Russian bombardment in recent weeks. Hundreds of people, dozens of whom are injured, are thought to be inside the steel-making complex.
The Russian news agency TASS says that according to the Ministry of Defense in Moscow, 80 civilians have now been rescued from the “territory” of the Azovstal plant and evacuated to a Russian controlled compound a few miles away
It’s unclear whether any of them came from within the plant itself, where hundreds of civilians have been under a weeks-long bombardment.
"Civilians evacuated by Russian servicemen from the Azovstal plant, who wished to leave for areas controlled by the Kiev regime, were handed over to representatives of the UN and the International Committee of the Red Cross," the ministry said.
The report followed comments from a Ukrainian commander inside the plant who said some civilians have been evacuated from the steel works after the introduction of a ceasefire.
It was hoped that these civilians, all women and children, would go to the "agreed destination" of Zaporizhzhia, Capt. Svyatoslav Palamar said.
CNN's Kostan Nechyporenko contributed to this report.