'Massive strike' on Ukraine's energy sector, says minister

Russia has launched a "massive strike" on Ukraine's energy infrastructure, the country's energy minister said, as explosions were reported in several cities.

Herman Halushchenko said on Facebook that attacks on energy facilities were "taking place all over Ukraine" and emergency power outages had been introduced.

Early on Thursday, the Ukrainian air force declared a nationwide air raid alert "due to the threat of missile danger".

Recent days have seen Russia carry out some 1,500 air strikes in Ukraine, hitting around half the country's regions, according to authorities.

The air force issued further warnings of rockets heading towards numerous regions around the country, including Rivne, Vinnytsia, Kropyvnytskyi, Balta, and Mykolaiv.

The mayor of Kharkiv, Igor Terekhov, said there was shelling of a civilian area in the city, while the mayor of Lutsk, Ihor Polishchuk, said multiple explosions had been heard.

Local media outlet Zerkalo Tyzhnya also reported that explosions had been heard in the key port city of Odesa, while regional governor Oleg Kiper urged residents to stay somewhere safe.