Irish rock star Bono praised Ukraine's fight for "freedom" during a performance at a central Kyiv metro station on Sunday, where the U2 frontman also delivered his own prayer "for peace."

The mini-concert took place as air raid sirens sounded in the Ukrainian capital and fighting raged in the east of the country.

Bono performed alongside U2 guitarist The Edge to a small crowd of fans, including members of the Ukrainian armed forces.