A Russian strike on a humanitarian support centre in eastern Ukraine killed three people, the emergencies service said Friday, revising their previous toll of five dead.

"The town of Kostyantynivka came under rocket fire during the night of March 24. One of the rockets hit a one-storey building," it said.

"Three people died and two people were injured as a result of the incident," the service said later.

It published images of a building with its roof caved in and debris all around.

It said the victims included "three internally displaced women from Bakhmut, Chasiv Yar and Opytne", nearby towns at the centre of the conflict.

The Russian army said in its daily report Friday that it had hit an "ammunition depot of foreign legion mercenary units" in Kostyantynivka.

Kostyantynivka is about 25 kilometres (15 miles) west of Bakhmut, an industrial city that has seen the longest and bloodiest battle of the Russian invasion.

A statement by the regional prosecutor said the Russian military had fired S-300 anti-aircraft missiles at Kostyantynivka.

Authorities in the southern region of Kherson, partly controlled by Russian forces, said one civilian had been killed in Russian strikes in the past 24 hours.