Russian hawks celebrate, casting the strikes as revenge for the Crimea bridge attack.

Russian hard-liners celebrated on Monday as missiles rained down on Ukrainian cities, saying the attacks were retaliation for the blast that partially destroyed Moscow’s bridge to Crimea and were a long-awaited sign that the Kremlin was intensifying its attacks against Ukraine’s critical infrastructure.

Ramzan Kadyrov — the bellicose leader of the Russian republic of Chechnya, who just days ago had railed against the military leadership in Moscow for ordering a retreat from a key city in eastern Ukraine — cheered that he was finally “satisfied with how the special military operation is ongoing,” using Russia’s official term for the war in Ukraine.

Sergei Aksynov, the head of Crimea, which Russia illegally annexed from Ukraine in 2014, said the attacks demonstrated that Russia’s approach to the war had changed. Had the Russian military targeted Ukraine’s civilian infrastructure “every day since the first day of the special military operation, we would have ended it all in May,” he wrote on Telegram.

For months, Russian state media, in tune with the official Kremlin line, has been claiming that Russian forces were only hitting military targets in Ukraine. That changed on Monday with Channel One, one of the country’s two main television networks, reporting the strikes against Ukrainian cities as their top story.

“Critical infrastructure facilities were damaged,” the anchor on a state television newscast said, narrating footage of smoke rising over central Kyiv.

It was a sign that — amid rising pressure from the war’s supporters that Russia escalate its assault — the Kremlin wanted Russians to know about the extent of Monday’s strikes.

Sergei Mironov, a hawkish senior lawmaker, said the attack on the bridge linking Russia to Crimea had shown that “we need to wage war.” The “terrorists” in Ukraine, he said, “must live in fear, they must understand that punishment is inevitable and unavoidable.”

Zakhar Prilepin, a prominent Russian writer, acidly wondered in his channel on Telegram, a social messaging app, if there was still a line of people in central Kyiv, which was hit by multiple strikes on Monday morning, waiting to take a picture in front of a poster of the burning bridge.

While many pro-Russian commentators have advocated a much tougher approach to the war since the invasion in February, their calls grew louder as Russia began to suffer painful setbacks in recent weeks.

As Ukraine has successfully targeted key elements of infrastructure used by Russia, including the Antonivka bridge over the Dnipro river near Kherson in southern Ukraine, many wondered why Russia could not do the same.

Some warned that it would be impossible for Russia to defeat Ukraine’s forces without knocking out bridges over the Dnipro, which Kyiv has used to deliver reinforcements and weapons provided by Western countries. The hard-liners’ criticism showcased how the Kremlin has found itself under increased pressure to deliver results as its ground forces have been in retreat for weeks.

In a speech on Monday, Mr. Putin said the strikes were in response to the attack against the bridge in Crimea — land that he claims as Russian.

“If attempts to carry out terrorist attacks on our territory continue, the measures taken by Russia will be tough and in their scale will correspond to the level of threats posed to the Russian Federation,” he said.

Some Russian commentators interpreted Mr. Putin’s statement as another warning sign from the Kremlin about further action. But Zastavny, a popular pro-Kremlin channel on Telegram, said that warnings “are just a half measure, an invitation to the enemy to go until the end.”

“If strikes against the Ukrainian infrastructure would be a limited one-off action and there won’t be systemic, the enemy will make his own conclusions,” the post said.

Oleg Tsaryov, a pro-Russian former deputy of the Ukrainian Parliament who fled the country in 2014, said the strikes against Ukrainian cities made him “angry, even furious toward the diabolical scriptwriters who managed to push us into a fratricidal, civil war.”

Aleksandr Khodakovsky, a native of Donetsk and a commander of Russian-backed separatist forces there in eastern Ukraine, said he didn’t feel joy when Russian missiles flew over Kyiv.

“I only repeat to myself: this is war,” he said in a post.