KYIV, Ukraine (AP) — Russian forces on Sunday fired rockets on the Mykolaiv region in southern Ukraine, killing at least one person, and a Russian diplomat called on Ukraine to offer security assurances so that international inspectors could visit a nuclear power station that has come under fire.

The Mykolaiv region is just to the north of the Russian-occupied city of Kherson, which Ukrainian forces have vowed to retake. The Ukrainian emergency service said one person was killed in shelling early Sunday of the Mykolaiv region settlement of Bereznehuvate.

As fighting steps up in southern Ukraine as Russia's war closes in on six months, concern has grown sharply about the Zaporizhzhia nuclear power plant, which is held by Russian forces and has been hit by sporadic shelling. Both Ukraine and Russia blame each other for the shelling, which officials say has damaged monitoring equipment and could lead to a nuclear catastrophe.

The Zaporizhzhia facility is Europe's largest nuclear power plant.

Russia's envoy to international organizations based in Vienna, Mikhail Ulyanov, called on Ukraine to stop attacking the plant in order to allow an inspection mission from the International Atomic Energy Agency.

“It is important that the Ukrainians stop their shelling of the station and provide security guarantees to members of the mission. An international team cannot be sent to work under continuous artillery shelling,” he was quoted as saying Sunday by Russian state news agency Tass.