Series of blasts heard in Ukraine's capital Kyiv

A series of blasts were heard in the Ukrainian capital Kyiv on Monday morning, Reuters reported. Regional authorities in northern, eastern and central Ukraine also reported missile strikes although reason for the blasts in Kyiv was not known.

Russia has stepped up missile attacks in recent weeks after blaming Ukraine for the explosion which damaged the Crimea bridge.

Smoke could be seen rising above Kyiv after about 10 explosions, Reuters reported.

Ihor Terekhov, the mayor of Kharkiv, said the city has been struck by two missiles which targeted "a critical infrastructure facility".