Russia launched a volley of missiles at Ukraine’s energy grid on Monday, knocking out power in several regions, officials said, in the latest in a months-long campaign of strikes by Moscow targeting civilian infrastructure.

Ukrainian air defence systems fired into the sky in multiple areas of the country but not all missiles were intercepted, as officials reported damage to electrical systems.

Following a grim routine, Ukrainians headed for bomb shelters in Kyiv and other cities. After about three hours, air-raid warnings were lifted in some parts of Ukraine.

Shortly after the all-clear was given, President Zelensky addressed the nation to praise both the military and utility workers fighting to keep the lights on. “Air defences shot down most of the rockets, and energy workers have already started to restore electricity,” he said.

Ukraine’s Air Force later said that it had shot down more than 60 missiles out of more than 70 fired. The strikes occurred hours after explosions were reported at two military bases deep inside Russia, including one that Ukraine said has been used as a staging ground for aircraft in previous attacks against Ukraine’s energy grid.

There was no immediate information on the cause of the blasts. By mid-afternoon, multiple reports surfaced in Ukraine of inbound missiles. A New York Times reporter south of Kyiv saw a cruise missile in flight travelling towards the capital.

Ukraine’s national energy company, Ukrenergo, said on Facebook that a “mass missile attack” had damaged electrical facilities.