(Reuters) -A Russian missile attack on an educational institution in the Ukrainian Black Sea port of Odesa on Monday killed four people and injured 28, local officials said.

Regional governor Oleh Kiper, writing on the Telegram messaging app, said four of the injured were in serious condition and receiving urgent treatment.

He said the injured included two children and a pregnant woman.

Pictures posted online showed an ornate building close to the seafront ablaze and smoke billowing skyward. Video footage, which could not be immediately verified, showed people receiving treatment on the street alongside pools of blood.

Ukrainian navy spokesperson Dmytro Pletenchuk, in a posting on a military Telegram channel, said the strike was conducted by an Iskander-M ballistic missile with a cluster warhead. These missiles are harder to intercept.

Public broadcaster Suspilne said the roof of the building, described as a law academy, had been nearly destroyed. It said the academy's president, a prominent former member of parliament, Serhiy Kivalov, was among the injured.

Odesa has been a frequent target of Russian missile and drone attacks, particular port infrastructure.

(Reporting by Yuliia DysaEditing by Ron Popeski, Ros Russell and Toby Chopra)