The drone that dropped explosives in the Black Sea town of Tyulenovo on Sunday night was inspected and deactivated by a special detachment assigned by the Bulgarian defense ministry on Monday.

The team from NATO member Bulgaria will decide how to dispose of it after inspection, according to a statement from the ministry, which also noted that the team had been sent at the request of the local government.

“We can certainly assume that it (the drone) is related to the war that Russia launched against Ukraine,” Defence Minister Todor Tagarev told reporters.

“This war is inevitably associated with increasing risks to our security,” he added.

Tagarev did not provide more detailed information on where the drone came from and how it reached Bulgaria.

The tourist resort of Tyulenovo is situated 70 kilometres (43 miles) south of the Romanian border and across the Black Sea from Crimea, the Ukrainian peninsula forcibly annexed by Russia in 2014 and now a regular target of Ukrainian drone attacks.

Police cordoned off the area on Sunday evening and restricted public access to local restaurant terraces, Marian Zhechev, mayor of Shabla municipality of which Tyulenovo is a part, told Nova TV.

He said the drone had been found on rocks next to moored boats at Tyulenovo, describing it as an “aircraft with standard ammunition”.

It was unclear whether the drone had fallen from the air or had been washed up by the sea currents.

Nova.bg web site quoted witnesses as saying that the drone was between 3 and 3.5 metres long and that it had a container with explosives attached to it.

Last week fragments of a suspected drone were found in Romania, after a new Russian attack on Ukraine’s Danube ports across the border.