Russia struck Ukraine's capital Kyiv with missiles early on Sunday for the first time in more than a month, while Ukrainian officials said a counterattack on the main battlefield in the east had retaken half of the city of Sievierodonetsk.

Dark smoke could be seen from many miles away after the attack on two outlying districts of Kyiv. Ukraine said the strike hit a rail car repair works, while Moscow said it had destroyed tanks sent by Eastern European countries to Ukraine.

In Sievierodonetsk, where Russia has concentrated its forces in recent weeks, Ukraine mounted a counterattack that it said took the Russians by surprise.