Explosions were also reported in Lviv, Ternopil and Zhytomyr in Ukraine's west, and in Dnipro in central Ukraine. The explosions appeared to be the result of missile strikes.
Russian President Vladimir Putin said if attacks continue against the country, then the response will be harsh. "Crimea bridge blast is an act of terrorism. Ukraine's special forces were behind the bridge attack. Ukraine has also tried to blow up Turkish Stream pipeline... If attacks continue against Russia, the response will be harsh," Reuters reported Putin as saying.
The Kremlin said that a huge missile salvo across Ukraine was launched by its forces was within the framework of what Russia calls its "special military operation" in Ukraine. While, the European Union said that Russia targeting civilians 'amounts to a war crime'.
Earlier in the day, President Volodymyr Zelenskyy said, "They (Russians) are trying to destroy us and wipe us off the face of the earth...destroy our people who are sleeping at home in Zaporizhzhia. Kill people who go to work in Dnipro and Kyiv."
"The air raid sirens do not subside throughout Ukraine. There are missiles hitting. Unfortunately, there are dead and wounded."
Kyiv Mayor Vitalii Klitchko reported explosions in the city's Shevchenko district, a large area in the center of Kyiv that includes the historic old town as well as several government offices.
"Several explosions in the Shevchenskivskyi district - in the centre of the capital," Klitschko said on the Telegram messaging app. "Details later."
#WATCH | Aftermath of multiple strikes in Ukraine's Kyiv today
President Volodymyr Zelenskyy says many people killed and injured in multiple strikes across the country today
At one of Kyiv's busiest road junctions, a massive crater had been blown in the intersection. Cars were destroyed, buildings were damaged and emergency workers were on the scene. Two cars and a van near the crater were completely wrecked, blacked and pitted from shrapnel.
Windows had been blown out of buildings at Kyiv's main Taras Shevchenko University. National Guard troops in full combat gear and carrying assault rifles were lined up outside an education union building.
Recent fighting has focused on the regions just north of Crimea, including Zaporizhzhia, where six missiles were launched overnight Saturday from Russian-occupied areas of the Zaporizhzhia region.
Russian President Vladimir Putin on Sunday called the attack that damaged the huge bridge connecting Russia to its annexed territory of Crimea.