International Red Cross convoy forced to turn back after failed attempt to evacuate Ukrainians trapped in Russia's siege of Mariupol

• A Red Cross convoy was forced to turn back after an attempt to evacuate Ukrainians from Mariupol.
• The organization called the convoy "desperately important" and said it will try again Saturday.

An International Committee of the Red Cross convoy was forced to turn around after it attempted to evacuate Ukrainian civilians trapped in the besieged southern port city of Mariupol, where many residents have gone weeks without heat, electricity and clean water.

"The ICRC team, which consists of three vehicles and nine personnel, did not reach Mariupol or facilitate the safe passage of civilians today," the humanitarian organization said in a statement on Friday.

ICRC personnel will try again on Saturday to reach Mariupol, which has been the center of a brutal assault by Russian forces for weeks.

"For the operation to succeed, it is critical that the parties respect the agreements and provide the necessary conditions and security guarantees," the ICRC said.

It added: "If and when the safe passage operation does happen, the ICRC's role as a neutral intermediary would be to accompany the convoy out from Mariupol to another city in Ukraine."

On Thursday, the ICRC said it had teams traveling to Mariupol with relief items and medical supplies. The organization said it was waiting until Friday to start the operation because of "logistical and security" reasons, "provided all the parties agree to the exact terms, including the route, the start time, and the duration."

The ICRC was slated to lead a convoy of around 50 buses from Mariupol full of civilians trying to escape the bombarded city.

"It's desperately important that this operation takes place," the ICRC said earlier. "The lives of tens of thousands of people in Mariupol depend on it."

But on Friday, the evacuation team was forced to return to nearby "Zaporizhzhia after arrangements and conditions made it impossible to proceed," the organization said in a statement.

It was not immediately clear if a specific incident forced them to turn around, or if it was the ongoing hostilities.

Russian forces have continuously shelled Mariupol, targeting schools, hospitals, and even a theater marked as a shelter with children inside.

The US State Department has suggested that Russian forces have "brutalized" the city because President Vladimir Putin is angry at Ukraine's fierce resistance amid the ongoing five-week-long war.

"Mariupol is, of course, a strategic location," State Department Spokesperson Ned Price said last week. "But there also may be an element of vengeance... against this population, with Putin perhaps having been under the misimpression — whether he was misinformed or just unwitting of reality — that his forces would not be greeted as anything other than the aggressors that they are."

Previous attempts to evacuate civilians or create humanitarian corridors from Mariupol have failed or been blocked by Russian forces, leading its mayor Vadym Boichenko to say Putin's forces are "playing" a "cynical game."

It's unclear exactly how many civilians have been killed in Mariupol since the Russian invasion began on February 24 — the United Nations said earlier in the week that there have been "high numbers of civilian casualties," but collecting and verifying information has been difficult.