Two drones entered Nato member Latvia from Russian territory and crashed on Thursday morning, the Latvian army has confirmed.
Latvia's Defence Minister Andris Spruds told national broadcaster LSM that the drones were "probably launched by Ukraine against targets in Russia."
Military jets from the multinational Nato Baltic air policing mission were subsequently summoned to the site.
Four empty oil tanks were damaged on Thursday morning at a storage facility in Rezekne, about 40 km (25 miles) from the Russian border. Possible debris of a crashed drone was found at the site, police and firefighters said.
The firefighters extinguished a smouldering area of around 30 square metres in one of the tanks.
Latvian authorities had issued drone alerts to residents along the Russian border at 4.09am local time (01.09 GMT) on Thursday, asking them to stay indoors.
All schools will be closed in Rezekne on Thursday, the municipality said.
Several stray Ukrainian drones hit Latvia and its Nato neighbours Estonia and Lithuania in late March. One slammed into a chimney at a local power station while another crash-landed in a frozen lake and exploded.
Latvian Prime Minister Evika Silina said on her X account at the time: “I am in close communication with the Minister of Defense, the National Armed Forces, and the responsible services, as well as the leaders of Estonia and Lithuania.
“An investigation into the incident is underway, but initial information suggests that a Ukrainian drone may have entered and crashed in Latvia's territory. There are no casualties.”
The three Baltic countries have never allowed their territories and airspace to be used for drone attacks against targets in Russia, their foreign ministers said in April.
Meanwhile Ukraine accused Russia of flouting a Kyiv-proposed ceasefire on Wednesday by carrying out dozens of battlefield assaults, air strikes and drone attacks.
Zelensky had floated the cessation, starting on 6 May, in response to Russian leader Vladimir Putin's own proposed ceasefire from 8 to 9 May to coincide with its Second World War victory commemorations.
In a statement, Zelensky said Russia – which did not confirm its adherence to Ukraine's proposal – had committed 1,820 violations by late morning on Wednesday.
“Russia's choice is an obvious spurning of a ceasefire and of saving lives," he said. Speaking later in his nightly video address, Zelensky said Russia "has responded to the proposal only with new strikes and new attacks" and Ukraine would determine "our entirely justified responses".
He said Ukraine was ready to work for peace but that "if the one person in Moscow who cannot live without war is interested only in a parade and nothing else, that is another matter".
“Russia has fought to the point where even their main parade now depends on us," he said.
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