Appeal for “maximum restraint” around the nuclear power plant in Russia’s Kursk region, the International Atomic Energy Agency (IAEA) said Friday Fighting is raging in Kursk after the invasion of Ukrainian forces.

“At this stage, I would like to appeal to all sides to show maximum restraint in order to avoid a nuclear accident,” IAEA chief Rafael Grossi said in a statement.

Earlier today, regional governor Alexei Smirnov announced that power had been cut in the city of Kurchatov, where the nuclear power plant, one of the largest in all of Russia, is located. In a post on Telegram, Smirnov says that debris from a Ukrainian drone fell into a power distribution substation in the Kursk region, knocking out power to the city of 42,000.

Debris Ukrainian drone fell into a power distribution substation in Russia’s Kursk region and caused a blackout in the city of Kurchatov, where the nuclear power plant is located, Smirnov said earlier.

In his post on Telegram, Smirnov says that the electricity supply in the city was interrupted today Friday of 42,000 inhabitants home to one of Russia’s largest nuclear power plants.

After the surprise invasion of Ukrainian forces in the Russian Kursk region, heavy fighting has been raging in the wider region for four days.