Ukraine's capital city Kyiv was rocked by multiple explosions early on Monday in an attack by "Kamikaze" drones, an Ukrainian official said.
Andriy Yermak, head of the presidential office of Ukraine, said kamikaze drones were attacking the city.
"The Russians think it will help them, but these actions look like desperation," Yermak said in a statement, blaming Russia for the attack, CNN reported.
Several residential buildings were damaged in the attack.
In a Telegram message, Kyiv mayor Vitali Klitschko said the "drone attack" caused a "fire in a non-residential building."
Kyiv says Moscow has used Iranian-supplied drones in the strikes against Kyiv, Vinnytsia, Odesa, Zaporizhzhia and other cities across Ukraine in recent weeks, and pleaded with Western countries to step up their assistance in the face of the new challenge, CNN reported.
At least three explosions were heard in the Ukrainian capital at around 6:45 a.m. local time on Monday as a result of apparent Russian strikes, according to CNN.
One of the blasts was in the Shevchenkivskyi district in the centre of the Ukrainian capital. In order to tackle the situation, emergency services have been sent on site.
The war between Russia and Ukraine has only escalated after a truck recently exploded on the Crimea road bridge, causing seven fuel tanks of a train heading to the Crimean Peninsula to catch fire. Three people were killed in the blast, which also led to the partial collapse of two spans of the road bridge.
The Crimean Bridge was opened in 2018 by President Vladimir Putin, four years after Moscow annexed Crimea and was designed to link the peninsula to Russia's transport network.
The 19-kilometre bridge, which runs across the Kerch Strait and connects Crimea with mainland Russia, consists of a railway and vehicle sections. It became fully operational in 2020.
Earlier, the transport ministry had said the bridge, which consists of two parallel routes for automobiles and trains, will possibly open to trains by 8 pm Moscow time (1700 GMT) on Saturday.