Russian missile strikes hit energy infrastructure in central and western parts of Ukraine Saturday morning, leaving hundreds of thousands of people without power, Ukrainian officials said.

Ukraine’s air force said in a statement that Russia launched a “massive missile attack” at 7 a.m. local time, targeting “critical infrastructure in different regions of the country.” The air force said it had managed to shoot down 18 cruise missiles launched by Russian troops.

Foreign Minister Dmytro Kuleba urged foreign capitals to boost Ukraine’s air defense capabilities, tweeting: “There should not be a minute of delay in capitals deciding on air defense systems for Ukraine.”

According to the Associated Press, the strikes have so far left residents without electricity in parts of Odesa, Cherkasy, Kropyvnitsky, Rivne, Khmelnytskyi and Lutsk.

The intensified missile attacks come as Russia’s invasion of Ukraine nears its eighth-month mark.

Meanwhile, authorities in Russia-occupied Kherson urged residents to “immediately leave the city” Saturday, according to media reports, as Ukrainian forces fight to retake the region.

For more than a week, the Russian-appointed authorities have been calling on Kherson residents to leave the city and, if possible, head to the annexed Crimea and Russian regions. But this is the first time the authorities have made a categorical demand to evacuate. The Ukrainian authorities accuse Russia of deporting the population.