<p>Kyiv: Ukraine's air defence units were engaged in trying to repel an overnight Russian attack on Kyiv, Ukraine's military and officials said early on Sunday.</p><p>"Stay in shelters!" Mayor Vitali Klitschko said on the Telegram messaging app.</p><p><em>Reuters</em>' witnesses heard several explosions in what sounded like air defence systems in operation.</p>
<p>Kyiv: Ukraine's air defence units were engaged in trying to repel an overnight Russian attack on Kyiv, Ukraine's military and officials said early on Sunday.</p><p>"Stay in shelters!" Mayor Vitali Klitschko said on the Telegram messaging app.</p><p><em>Reuters</em>' witnesses heard several explosions in what sounded like air defence systems in operation.</p>