Air raid alerts have been sounded in Ukraine on Monday morning, according to Ukrainian media.

At 06:15 AM (Kiev time), air raid alerts were activated in the Zhytomyr, Vinnitsa, Cherkasy, Kirovograd, Nikolayev and Odessa regions. In addition, Volyn, Poltava and Ivano-Frankivsk authorities confirmed the air raid alert. 

Explosions were heard in separate areas, including the cities of Kiev, Nikolayev and Odessa. In the Nikolayev region, industrial infrastructure facilities, including a fuel depot, caught fire after the explosions sounded.

Read next: Russian forces down Su-25 aircraft, eliminate 400+ Ukrainian forces

The mayor of Kiev, Vitali Klitschko said that traffic was suspended in the capital's center. 

"The traffic is blocked on sections of several streets in the center of the capital. I call upon the residents of Kiev to avoid the city center without an urgent need," Klitschko said on Telegram.

The mayor, in an earlier message, said that several explosions occurred in the district of Shevchenkivskyi in Kiev. 

Russia has been targeting Ukraine with precision strikes against its infrastructure since last week. The bombing was carried out in response to the bombing operation that destroyed part of the Crimean Bridge, which links the Russian mainland to the peninsula, which is of great strategic importance.

Read more: Ukraine military intelligence behind Crimea bridge attack: FSB

On Saturday, Ukrenergo stated that Kiev's energy infrastructure has been damaged due to a morning missile attack. Residents across Ukrainian cities were told to cut down on electricity consumption for the time being.

Russian President Vladimir Putin said on Friday that Moscow would now make do with the massive strikes on vital Ukrainian infrastructure, adding that new, intense bombing was not necessary "at the moment".