Ukrainian President Volodymyr Zelensky has accused Russia of “barbarism” after a missile attack on the port of Odesa.
The strike came just hours after Moscow and Kyiv signed deals to allow grain exports to resume from the port.
Russia has been widely condemned over the strike in which Russian Kalibr cruise missiles hit the port’s infrastructure.
Odesa regional governor Maksym Marchenko said an unspecified number of people were injured in the attack.
In his nightly address on Saturday night Volodymyr Zelensky described the “cynical” attack as “barbarism”.
He said Russia cannot be trusted to implement the landmark deal agreed to resume grain exports from Black Sea ports.
“If anyone in the world could still say that some kind of dialogue with it, with Russia, some kind of agreements are needed, see what is happening,” he said.
“Today’s Russian Kalibr missiles have destroyed the very possibility for such statements. The occupiers can no longer deceive anyone.”
The United Nations, European Union, US and UK all condemned the strikes, with UK foreign secretary and prime ministerial hopeful Liz Truss describing the attack as “appalling”.
It is not clear how the air strikes will affect the plan to resume shipping Ukrainian grain by sea in safe corridors out of three Ukrainian Black Sea ports: Odesa, Chernomorsk and Yuzhny.
Ukraine and Russia signed identical deals on Friday with the UN and Turkey in Istanbul backing the plan, which UN Secretary-General Antonio Guterres hailed as “a beacon of hope” for a world in which food prices are rising rapidly.
Command spokeswoman Nataliya Humenyuk said no grain storage facilities were hit in Odesa, but Turkey’s defence minister said Ukrainian authorities had told him one missile struck a grain silo and another landed nearby. However, neither affected loading at Odesa’s docks.
The head of Mr Zelensky’s office, Andriy Yermak, said on Twitter that the Odesa strike, coming so soon after the endorsement of the Black Sea deal, illustrates “the Russian diplomatic dichotomy”.
Mr Guterres’s office said the UN chief “unequivocally condemns” the strikes.
A statement said: “All parties made clear commitments on the global stage to ensure the safe movement of Ukrainian grain and related products to global markets. These products are desperately needed to address the global food crisis and ease the suffering of millions of people.”
Ukraine is a major grain exporter, but because of the war, about 20m tonnes of grain is trapped in its ports, unable to leave because of Russian forces. This has lead to food shortages and price rises across Africa, which usually relies on Ukraine and Russia for wheat.
Under Friday’s deal, Russia agreed not to target ports while grain shipments were in transit.
Ukrainian Foreign Ministry spokesman Oleg Nikolenko said: “It took less than 24 hours for Russia to launch a missile attack on Odesa’s port, breaking its promises and undermining its commitments before the UN and Turkey under the Istanbul agreement.
“In case of non-fulfilment, Russia will bear full responsibility for a global food crisis.”
He described the missile strike on the 150th day of Russia’s war in Ukraine as Russian President Vladimir Putin’s “spit in the face of UN Secretary-General Antonio Guterres and Turkish President Recep Tayyip Erdogan, who made great efforts to reach agreement”.
US Ambassador to Ukraine Bridget Brink denounced the strike on Odesa’s port as “outrageous”.
She tweeted: “The Kremlin continues to weaponize food. Russia must be held to account.”
US Secretary of State Antony Blinken said the attack casts serious doubt on the credibility of Russia’s commitment to the deal and undermines the work of the UN, Turkey and Ukraine.
“Russia bears responsibility for deepening the global food crisis and must stop its aggression and fully implement the deal to which it has agreed,” he said.