A wave of Russian drone and missile strikes on Ukraine's southern coast damaged port and industrial infrastructure, officials said Tuesday, hours after Moscow refused to extend a deal allowing the safe export of grain from the region.

Six Kalibr missiles "launched from the waters of the Black Sea at Odesa" were destroyed by air defences, Ukraine's southern command said in a statement.

"Unfortunately, the debris of the downed missiles and the blast wave from the downing damaged the port infrastructure facilities and several private homes," it added.

It did not specify exactly where the port infrastructure facilities or homes were located.

An elderly man was injured in his home and was receiving treatment, it said.

The Odesa region in southern Ukraine is home to maritime terminals that were key to the expired grain export agreement between Moscow and Kyiv.

An "industrial facility" in the southern port city of Mykolaiv was hit in the overnight attack according to local governor Vitaliy Kim.

Mykolaiv is located on the Black Sea, about 170 kilometres (100 miles) from Moscow-annexed Crimea.

Russian forces have frequently targeted it since the start of Moscow's invasion in February 2022.

Sergiy Bratchuk, spokesman for the Odesa military region, had previously reported air defences had been activated in the area.

Russia was "attacking the south of Ukraine with attack drones," head of the Odesa region's military administration, Oleg Kiper, said on Telegram.

He warned residents to stay in shelters.

Air alerts were also announced in Mykolayiv, Kherson, Zaporizhzhia, Donetsk, Kharkiv, Dnipropetrovsk, Poltava, Kirovograd, and Cherkasy.

Russia's invasion last year saw Ukraine's Black Sea ports blocked by warships until the agreement, signed in July 2022, allowed for the passage of critical grain exports.

The deal expired at midnight in Istanbul (2100 GMT) after Russia refused an extension, arguing that the parts of the deal allowing the export of Russian food and fertilisers had not been honoured.