CNN
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At least five people were killed and more than 30 others wounded in a Russian missile attack on the Black Sea port city of Odessa on Monday, Ukrainian authorities said.

Dramatic video footage of the attack, released by the Ukrainian Prosecutor General's Office, showed dozens of small bombs exploding within seconds of each other in an area near the waterfront.

Other videos and photos shared by officials showed flames engulfing the conical towers and roof of an educational institution known locally as “Harry Potter Castle” because of its resemblance to a Scottish baronial pile.

Ukrainian authorities believe Russia It used an Iskander ballistic missile and cluster munitions to carry out the attack.

“Metal fragments and missile debris were recovered in a radius of 1.5 kilometers (about one mile) from the site of the attack,” Ukrainian Prosecutor General Andriy Kostin said. He added that “the investigation has reasons to believe” that the Russian army used cluster munitions with the aim of causing a large number of casualties.

He added that two children and a pregnant woman were among 30 people injured in the attack.

Nearly 20 residential buildings and infrastructure facilities were also damaged by the strike.

The use, transfer and production of cluster munitions is prohibited under an international treaty known as the Cluster Munitions Convention. However, neither party – nor the United States – signed the agreement.

Cluster munitions have been used by both sides in the war and have been transferred to Ukraine Provided by the United States as part of a military aid package last year.

Meanwhile, Russian officials say air defenses in Crimea successfully intercepted a major missile and drone attack by Ukraine.

Kremlin-appointed Sergei Aksyonov, the top civilian official in occupied Crimea, warned people against getting close to possible unexploded ordnance, while one of his officials urged people not to film or post videos of Russian air defenses in action.

Russian military bloggers said the targets were airfields.

The bridge linking Crimea to Russia, a vital artery to supply Russia's ongoing war effort, was temporarily closed to traffic, but has since reopened.

Russian officials said the attack was carried out primarily using six US-supplied Army Tactical Missile Systems (ATACMS), all of which they said were successfully shot down by air defenses.

Ukraine did not comment, and CNN was unable to verify Russia's claims. Unusually, there were almost no videos or photos of the explosions.

This is a developing story and will be updated.