Moscow launched a large-scale attack on Ukraine’s energy infrastructure Friday, with a mass barrage of 99 drones and missiles hitting regions across the country, Ukraine’s armed forces said.

Air raid warnings rang out across the nation, with 10 Ukrainian regions coming under fire, the country’s interior minister, Ihor Klymenko, said.

Russia has escalated its attacks on Ukraine in recent days, launching several missile barrages on the capital, Kyiv, and hitting energy infrastructure across the country in apparent retaliation for recent Ukrainian aerial attacks on the Russian border region of Belgorod. Such sporadic attacks, however, have been common throughout the war.