Long-range missiles struck Ukraine's energy, military and communications facilities on Monday morning, Russian President Vladimir Putin told a security meeting later in the day.

The strikes were retaliation for what he called Ukraine's "terrorist attack" at the Crimea Bridge, an attack for which Ukraine has not claimed responsibility. He promised a "harsh" response to any further such attacks.

Russia's defense ministry said it hit "all designated targets" in the massive missile attack and the goals had been achieved.

Missiles tore into busy intersections, parks and tourist sites in the center of the capital Kyiv. Explosions were reported in Lviv, Ternopil and Zhytomyr in western Ukraine, Dnipro and Kremenchuk in central Ukraine, Zaporizhzhia in the south and Kharkiv in the east. 

A total of 14 people were killed and 97 were injured, the State Emergency Service of Ukraine reported. 

Ukrainian President Volodymyr Zelenskyy said on Monday the attacks during rush hour were deliberately timed to kill people and knock out Ukraine's power grid. 

Ukrainian Prime Minister Denys Shmyhal said 11 major infrastructure targets were hit in eight regions, leaving swaths of the country with no electricity, water or heat. He promised to restore utilities as quickly as possible.

As it tried to end blackouts, Ukraine halted electricity exports to the European Union, at a time when the continent already faces surging power prices that have stoked inflation, hampered industrial activity and caused sky-high consumer bills.

(With input from Reuters)