Russia has announced a three-day ceasefire in the besieged Ukrainian port city of Mariupol to allow the evacuation of civilians from a steel plant in the city.
Russia’s Defense Ministry said in a statement that a humanitarian corridor would be open from 08:00 to 18:00 local time (0500 to 1500 GMT) Thursday, to allow civilians to flee the Azovstal steelworks.
During this period, Russian forces would cease any military activity and withdraw units to a safe distance, the ministry added.
The announcement came hours after Mariupol Mayor Vadym Boichenko said heavy fighting was taking place at the plant, where the city's last defenders and some civilians are holding out.
Russia was attacking with heavy artillery, tanks, planes, and ships off the coast, he told Ukrainian television on Wednesday. "There are local residents there, civilians -- hundreds of them there," he added. "There are children waiting for rescue. There are more than 30 kids."
On April 25, Russia had announced a ceasefire around the giant fortress-like Azovstal in Mariupol to allow a civilian evacuation from the flashpoint industrial area.
Those who still remain holed up in Azovstal’s underground bunkers are believed to be running out of water, food, and medicine.
The city has been the scene of some of the heaviest fighting between the two sides since the onset of Russia’s military operation in Ukraine in late February.
United Nations humanitarian coordinator for Ukraine Osnat Lubrani said more than 300 civilians had been evacuated from Mariupol and the surrounding areas on Wednesday as part of a joint UN-Red Cross operation.
"While this second evacuation of civilians from areas in Mariupol and beyond is significant, much more must be done to make sure all civilians caught up in fighting can leave, in the direction they wish," Lubrani said.
Pascal Hundt, head of the International Committee of the Red Cross (ICRC) delegation in Ukraine also said, "We are relieved that more lives have been spared."
"We welcome the renewed efforts of the parties with regards to safe passage operations. They remain crucial and urgent in light of the immense suffering of the civilians."
It was not clear if further UN evacuations were planned.
Meanwhile, Denys Prokopenko, commander of the nationalist Azov regiment, has vowed to never surrender the plant.
"The situation is extremely hard. However, we will continue carrying out the order to keep up our defenses no matter what," he said in a video posted on Wednesday.
In an early morning address on Thursday, Ukrainian President Volodymyr Zelenskiy said civilians, including women and children, were still trapped inside Mariupol and a prolonged ceasefire was needed to ensure their evacuation.
"It will take time simply to lift people out of those basements, out of those underground shelters. In the current conditions, we cannot use special equipment to clear the debris. Everything is done manually," Zelensky said.
The latest development comes as the European Union (EU) member states have debated a proposed ban on Russian oil, the bloc's toughest move yet over Moscow's offensive against its neighbor.
The Kremlin has said Russia is weighing various responses to the EU plan, adding that the measures would be costly for European citizens.
Russian President Vladimir Putin announced the military offensive in Ukraine on February 24. Western countries have responded by backing Ukraine with cash and increasingly heavy weaponry while imposing sanctions against Russia.
The conflict in Ukraine has killed thousands of people and displaced more than 13 million, creating the worst refugee crisis in Europe since World War II.