Russia retaliated Monday for what it claimed was a Ukrainian terrorist attack on a critical bridge by unleashing its biggest and most widespread attacks against Ukraine in months. The lethal barrage against multiple cities smashed civilian targets, knocking out power and water, shattering buildings and killing at least 11 people.

Ukraine’s Emergency Service said 64 people were wounded across the country in the morning attacks — the biggest and broadest since the early days of the war.

Though some missiles apparently targeted energy facilities, others struck civilian areas during the morning rush-hour. One hit a playground in downtown Kyiv and another struck a central building of a local university.

Andriy Yermak, a senior adviser to President Volodymyr Zelenskyy, said there was no “practical military sense” in the strikes and Russia’s goal was to cause a “humanitarian catastrophe.”

Russian President Vladimir Putin said the strikes were in retaliation for what he called Kyiv’s “terrorist” actions — a reference to Ukraine’s attempts to repel Moscow’s invasion forces, including an attack Saturday on a key bridge between Russia and the annexed Crimean Peninsula that Putin called a “terrorist act” masterminded by Ukrainian special services.

Putin vowed a “tough” and “proportionate” response should Ukraine carry out further attacks that threaten Russia’s security. “No one should have any doubts about it."

But one expert told Spectrum News that Putin's attacks "really demonstrate his weakness right now" in the monthslong conflict.

"I think it's pretty clear that Putin is losing the conflict," said Robert Orttung, a research professor at Elliott School of International Affairs at George Washington University. "And Ukrainians are demonstrating greater and greater capacity to attack them to attack their supply lines to inflict real military damage under troops."

"The attacks that Putin is responding with demonstrate his own weakness because he is just attacking cities," he added. "He's attacking civilian infrastructure. He's not using precision guided missiles. I think his attacks really demonstrate his weakness right now."

President Joe Biden condemned the attacks in a statement Monday, calling on Russia to cease its "unprovoked aggression immediately and remove its troops from Ukraine."

"These attacks killed and injured civilians and destroyed targets with no military purpose," Biden wrote. "They once again demonstrate the utter brutality of Mr. Putin’s illegal war on the Ukrainian people."

"We offer our condolences to the families and loved ones of those who were senselessly killed today, as well as our best wishes for the recovery of those who were wounded," Biden continued. "These attacks only further reinforce our commitment to stand with the people of Ukraine for as long as it takes. Alongside our allies and partners, we will continue to impose costs on Russia for its aggression, hold Putin and Russia accountable for its atrocities and war crimes, and provide the support necessary for Ukrainian forces to defend their country and their freedom."

The White House confirmed later Monday that President Biden spoke with President Zelenskyy, with the U.S. leader pledging "to continue providing Ukraine with the support needed to defend itself, including advanced air defense systems."

Speaking in a video call with members of Russia’s Security Council, Putin said the Russian military launched “precision weapons” from the air, sea and ground to target key energy and military command facilities.

But the intense hours-long barrage on major cities hit residential areas and critical infrastructure facilities alike, portending a major surge in the war amid a successful Ukrainian counteroffensive in recent weeks.

The Ukrainian General Staff said 84 cruise missiles and 24 drones were use in the barrage. Ukrainian forces shot down 56 aerial targets, it said.

Putin, whose partial mobilization order earlier this month triggered an exodus of hundreds of thousands of men of fighting age from Russia, stopped short of declaring martial law or a counterterrorism operation as many had expected.

Moscow’s war in Ukraine is approaching its eight-month milestone, and the Kremlin has been reeling from humiliating battlefield setbacks in areas of eastern Ukraine it is trying to annex.

Blasts struck in the capital’s Shevchenko district, a large area in the center of the city that includes the historic old town as well as several government offices, Mayor Vitali Klitschko said.

Some of the strikes hit near the government quarter in the symbolic heart of the capital, where parliament and other major landmarks are located. A glass tower housing offices was significantly damaged, most of its blue-tinted windows blown out.

Russian forces targeted civilian areas and energy facilities in 10 cities, Ukrainian President Volodymyr Zelenskyy said in a video address. The Russians “chose such a time and such targets on purpose to inflict the most damage,” Zelenskyy said.

The morning strikes sent Kyiv residents into bomb shelters for the first time in months. The city’s subway system stopped train services and again made the stations available as places for refuge.

While air raid sirens have continued throughout the war in cities across the country, in Kyiv and elsewhere many Ukrainians had begun to ignore their warnings after months of calm.

That changed on Monday morning. The attacks struck Kyiv at the start of the morning rush hour, when commuter traffic was beginning to pick up. At least one of the vehicles struck near Kyiv National University appeared to be a commuter minibus, known as a “marshrutka,” a popular alternative to the city’s bus and metro routes.

Nearby, at least one strike landed in Shevchenko Park, leaving a large hole near a children’s playground.

Among the targets hit was the Klitschko pedestrian bridge — a landmark in central Kyiv with its glass panels. Closed-circuit television footage showed a huge explosion as the bridge was struck, and a man running away after the blast.

Elsewhere, Russia targeted civilian areas and energy infrastructure as air raid sirens sounded in every region of Ukraine except Russia-annexed Crimea, for four straight hours — an attack that spanned from Kharkiv in the east to Lviv in the west, near the Polish border.

Associated Press journalists in Dnipro city saw the bodies of multiple people killed at an industrial site on the city’s outskirts. Four people were killed and 19 injured in the city, local officials said.

Witnesses said one missile landed in front of a bus during the morning rush hour. Despite heavy damage to the vehicle, officials said no passengers were killed.

Natalia Nesterenko, a mathematician, said she saw one missile fly by her Dnipro apartment balcony as she was working in her kitchen. Then she heard two explosions.

“It’s very dangerous. I immediately called my kids to see how they are because anyone can be hit. Women, children,” she said.

Kharkiv was hit three times, Mayor Ihor Terekhov said. The strikes knocked out the electricity and water supply. Energy infrastructure was also hit in Lviv, regional Gov. Maksym Kozytskyi said.

Three cruise missiles launched against Ukraine from Russian ships in the Black Sea crossed Moldova’s airspace, said the country’s foreign affairs minister, Nicu Popescu.

The attacks brought out a fresh bout of international condemnation of Russia. The Group of Seven industrial powers scheduled a video conference Tuesday on the situation, which Zelenskyy will address.

French President Emanuel Macron expressed “extreme concern.” British Foreign Secretary James Cleverly tweeted that “Russia’s firing of missiles into civilian areas of Ukraine is unacceptable.”

“Russia once again has shown to the world what it stands for. It is terror and brutality,” said European Commission President Ursula von der Leyen.

Some feared Monday’s attacks may just be the first salvo in a renewed Russian offensive. As a precautionary measure, Ukraine switched all schools to online learning until at least the end of this week.

"Putin, I think, has lost control of the narrative right now, and he simply doesn't have a lot of options to respond to the Ukrainians with," Orttung said. "He sent in his best military troops at the beginning and they've they've not been able to perform. Now he's mobilizing people who are untrained and not really interested in going to fight for him, so he is running out of options."

Orttung said that short of these kind of attacks, Putin "doesn't really have much else he can do besides going nuclear," which he acknowledged the Russian leader has been threatening, but noted that "the West is responding correctly by not being cowed by those threats."

In an ominous move, Belarusian President Alexander Lukashenko announced Monday that he and Putin have agreed to create a joint “regional grouping of troops.” He offered no details.

Lukashenko repeated his claims that Ukraine is plotting an attack on Belarus, sparking fears he would take preemptive action. His defense minister, Viktor Khrenin, later issued a video warning Ukraine not to provoke Belarus, but added, “We don’t want to fight.”