KYIV - At least two explosions rocked Kyiv on Friday and air raid sirens blared as African leaders began a peace mission, hoping to mediate between Ukraine and Russia.

The African delegation, which includes leaders from South Africa, Senegal, the Comoros and Egypt, was expected to meet Ukrainian President Volodymyr Zelenskiy and then hold talks Russian President Vladimir Putin in St Petersburg on Saturday.

A Reuters witness in central Kyiv said he heard two explosions. Mayor Vitali Klitschko also reported explosions in the central Podil district, and warned that more missiles were headed towards the capital.

Another Reuters correspondent in the capital saw the smoke trail of two missiles in the air. It was not clear if those missiles were fired by Russia or by Ukrainian air defences.

A Reuters television crew saw the African leaders arriving in Kyiv in a convoy of cars and entering a hotel to use its air-raid shelter.

The leaders had begun their visit with a trip to Bucha, near Kyiv, which is one several places where Ukraine says Russian troops committed large-scale atrocities following their full-scale invasion in February 2022. Russia denies the allegations.

The African peace mission, which includes South African President Cyril Ramaphosa and Senagal President Macky Sall, could propose a series of "confidence building measures" during initial efforts at mediation, according to a draft framework document seen by Reuters.

The document states that the objective of the mission is "to promote the importance of peace and to encourage the parties to agree to a diplomacy-led process of negotiations".

Those measures could include a Russian troop pull-back, removal of tactical nuclear weapons from Belarus, suspension of implementation of an International Criminal Court arrest warrant targeting Putin, and sanctions relief, it indicated.

A cessation of hostilities agreement could follow and would need to be accompanied by negotiations between Russia and the West, the document stated.

The mission is being launched shortly after the start of a Ukrainian counteroffensive that has pushed Russian forces back in some areas though Kyiv has regained only a fraction of the territory Russian forces occupy in Ukraine.

Kyiv says its own peace initiative, which envisages the withdrawal of Russian troops from Ukrainian land, must be the basis for any settlement of the war.

(Additional reporting by Dan Peleschuk, Editing by Timothy Heritage)