• But the initiative comes just as Kyiv launches its counter-offensive and fighting intensifies.
• The alert came after the Ukrainian air force said several Russian Kalibr missiles had been launched from the Black Sea and were "heading north" towards Kyiv.
Seven African leaders will meet President Zelensky in Kyiv, before heading to Russia tomorrow on a peace mission.
The group - which includes leaders from South Africa and Egypt - has agreed to engage with Zelensky and Putin on a ceasefire and lasting peace.
But the initiative comes just as Kyiv launches its counter-offensive and fighting intensifies.
The alert came after the Ukrainian air force said several Russian Kalibr missiles had been launched from the Black Sea and were "heading north" towards Kyiv.
Russian missile attacks ramped up this week on Kyiv, Odesa, and President Zelensky’s hometown of Kryvyi Rih, killing several people.
Olexander Scherba, a Ukrainian diplomat has tweeted: "Sirens now. Putin welcoming African leaders in Kyiv."
The mission is an unusual burst of activism given Africa's largely hands-off approach to a conflict that many here see primarily as a confrontation between Russia and the West.
It is also a rare attempt at diplomatic intervention outside the continent - a "welcome development" given Africa's growing demand to have a bigger voice at the UN and other international organisations, says Murithi Mutiga, Africa director at the International Crisis Group (ICG) think-tank.
Meanwhile, a BBC investigation has found that at least 25,000 Russian soldiers have been killed in Ukraine - four times the official figure released by Moscow.
Nato defence ministers are meeting in Brussels today.
And the St Petersburg International Economic Forum is taking place, with President Putin expected to make the keynote speech.
This peace mission is being facilitated by the Brazzaville Foundation - an independent non-profit organisation whose goal is to develop initiatives to prevent conflict, mainly in Africa.
It is led by Frenchman Jean-Yves Ollivier, who has previously helped secure the release of hostages in the Central African Republic and mediate a power-sharing deal in the Democratic Republic of Congo
When it comes to the war in Ukraine, the foundation has stressed the need for dialogue, and its members have met both representatives of Ukraine and Russia over the past few months.
The foundation’s goal is “to facilitate a resumption of talks between the two countries”, according to its website, and its members hope to make progress on that front during these visits to Kyiv and Moscow.