Air raid warnings sounded throughout Ukraine on Tuesday as residents braced for more potential missile strikes after Russia targeted approximately a dozen cities in recent days.

Ukrainians were sent scurrying toward shelters as sirens sounded and mobile phones blared warnings to take cover.

The Ukrainian air force said Russian bombers over the Caspian Sea launched missiles toward Ukraine early Tuesday, but at least four of the missiles were shot down, according to The Associated Press.

Serhiy Borzov, the governor of the Vinnytsia region, also told the AP there was an early morning air strike in his region.

Russian President Vladimir Putin launched the deadly mass strikes on Ukraine after an explosion destroyed a portion of a key bridge connecting the Russian mainland to the Crimean Peninsula over the weekend.

Putin blamed the bridge explosion on Ukraine and called it a “terrorist” attack before vowing to retaliate further if Russia was provoked.

At least five people died from the strikes in the Ukrainian capital of Kyiv, where residents had been enjoying months of relative calm with fighting in the war mostly focused in the eastern region of the country.

Kremlin war hawks are demanding more strikes on Ukraine after Russia has suffered humiliating setbacks in the war, the AP reported, with some even celebrating the attacks on civilians.

The international world condemned the mass strikes on civilian populations, noting that targeting civilians is a war crime.

The explosion on the Kerch Bridge, which Putin himself drove across during a 2018 opening ceremony, was a monumental and symbolic message to Russia, analysts noted.