KYIV, UKRAINE -- Ukraine's President Volodymyr Zelenskyy on Monday condemned Russia's overnight and early morning barrage on his country as "vile" and said it involved over 100 missiles of various types and about 100 "Shahed" drones.

Ukraine's leader said there were deaths and dozens of injuries and that the attack caused a lot of damage to Ukraine's energy sector.

"Like most previous Russian strikes, this one was just as vile, targeting critical civilian infrastructure. Most of our regions -- from the Kharkiv region and Kyiv to Odesa and our western regions," Zelenskyy said.

The barrage began around midnight and continued beyond daybreak in what appeared to be Russia's biggest attack against Ukraine in weeks.

Russian forces fired drones, cruise missiles and hypersonic ballistic Kinzhal missiles at 15 Ukrainian regions -- more than half the country, Ukraine's Prime Minister Denys Shmyhal said Monday morning.

"The energy infrastructure has once again become the target of Russian terrorists. Unfortunately, there is damage in a number of regions," Shmyhal said, adding that Ukraine's state-owned power grid operator, Ukrenergo, has been forced to implement emergency power cuts to stabilize the system.

He called on Ukraine's allies to provide Kyiv with long-range weapons and permission to use them on targets inside Russia.

"In order to stop the barbaric shelling of Ukrainian cities, it is necessary to destroy the place from which the Russian missiles are launched," Shmyhal said. "We count on the support of our allies and will definitely make Russia pay."

According to Ukraine's air force, there were multiple groups of Russian drones moving toward eastern, northern, southern, and central regions of Ukraine, followed by multiple cruise and ballistic missiles.

Explosions were heard in the capital, Kyiv. Power and water supplies in the city have been disrupted by the attack, Kyiv Mayor Vitali Klitschko said.

At least three people were killed -- one in the western city of Lutsk, one in the central Dnipropetrovsk region and one in the partially occupied Zaporizhzhia region in the southeast, according to local officials. Thirteen others were wounded -- one in the Kyiv region that surrounds the Ukrainian capital, five in Lutsk, three in the southern Mykolaiv region and four in the neighbouring Odesa region.

Blackouts and damage to civilian infrastructure and residential buildings were reported across the country, from the region of Sumy in the east, to the Mykolaiv and Odesa regions in the south, to the region of Rivne in the west.

In Sumy, a province in the east that borders Russia, local administration said that 194 settlements were in a full power blackout, while 19 others had a partial blackout.

Ukraine's private energy company, DTEK, introduced emergency blackouts, saying in an online statement that "energy workers throughout the country work 24/7 to restore light in the homes of Ukrainians."

In the wake of the barrage and the power cuts, regional officials all across Ukraine were ordered to open "points of invincibility" -- shelter-type places where people can charge their devices and get refreshments during energy blackouts, Prime Minister Shmyhal said. Such points were first opened in Ukraine in the fall of 2022, when Russia targeted the country's energy infrastructure with weekly barrages.

In neighbouring Poland, the military said Polish and NATO air defences were activated in the eastern part of the country as a result of the attack.

In Russia, in the meantime, officials reported a Ukrainian drone attack overnight and on Monday morning.

Four people were injured in Russia's central region of Saratov, where drones hit residential buildings in two cities. One drone crashed into a residential high-rise in the city of Saratov, and another hit a residential building in the city of Engels, home to a military airfield that had been attacked before, local officials said.

Russia's Defence Ministry said that a total of 22 Ukrainian drones were intercepted overnight and in the morning over eight Russian regions, including the Saratov and Yaroslavl regions in central Russia.