Drones coming from Russian airspace hit their territories, Latvian and Estonian authorities said on Wednesday.
One drone "struck the chimney of the Auvere power plant" in Estonia, the country's internal security ISS said in a statement, while another fell on Latvian territory.
The Auvere power plant, operated by the Enefit Power group, is located in northeastern Estonia, near the town of Narva on the Russian border.
"These are the effects of Russia’s large-scale war of aggression," said ISS Director General Margo Palloson, expressing concern about "the occurrence of such incidents in the future."
Prosecutors are supervising an investigation into the incident.
Meanwhile, Latvian Prime Minister Evika Silina said in a post on X that the drone that fell on Latvian territory was apparently Ukrainian.
Ukraine carried out several strikes against Russia overnight, in particular targeting the major northwestern port of Ust-Luga on the Gulf of Finland.
Latvia's air force said it had identified an unmanned aerial vehicle travelling in Latvian airspace from Russia and that its early warning system detected a sound similar to an explosion in the Kraslava region.
Kraslava is in the southeastern corner of Latvia bordering Belarus, an ally of Moscow.
Latvian authorities said there were no injuries or damage caused by the explosion and that the drone's wreckage had been recovered.
