An air defense system has been activated in Kiev, the city administration said in a telegram channel.
At 22.45 Moscow time on June 8, an air alert was announced in the city.
"We ask residents and guests of the city to stay in the shelter of the alarm signal," the administration said in a statement.
The air alert was also announced in Kharkiv, the head of the regional military administration of the Kharkiv region Oleg Sinegubov said in a telegram channel.
According to him, explosions were heard in some parts of the city. Later, Sinegubov wrote about a fire on the outskirts of Kharkov.