Caritas-Spes offered its condolences “to the parents of the innocent victims.”
The deaths were also reported by Caritas Ukraine, which has offered humanitarian assistance through the Ukrainian Greek Catholic Church since 1992 and oversees the office in Mariupol.
It said on its Twitter account: “Caritas center in Mariupol was destroyed. There are victims. The building was shot by a Russian tank.”
“At that time, there were people who were hiding from the shelling and were looking for a safe place. Seven people died, including two of our accounting staff.”
Mariupol, a port city in southeastern Ukraine, was attacked by Russian forces on Feb. 24, the first day of the full-scale invasion of the country.
Ukrainian fighters have continued to resist the Russian advance on the city despite relentless bombing, which has destroyed many buildings and killed thousands of people.