“It’s sure, because we had another one four or five weeks ago that didn’t explode. We compared and they are completely identical,” Romania’s President Nicosur Dan told the BBC World Service.
The drones are used to target Ukrainian ports on the other side of the river Danube that are vitally important to Ukraine’s grain exports.
On Friday, Romania tracked a swarm of 43 of them as they travelled from east to west.
“One hit by the Ukrainian army changed direction and passed to Romanian territory. That is sure,” Dan said.
Romania’s Nato allies have called Russia’s conduct “reckless” and stressed that Moscow’s war of aggression was to blame for what happened.
In Washington, though, US Secretary of State Marco Rubio ignored reporters’ requests to comment.
And there is clearly caution in the response, as well as condemnation.
No-one is accusing Moscow of mounting a deliberate attack on Romania.
And whilst government sources in Bucharest tell us they considered invoking Article 4 of the Nato treaty, which would trigger an emergency meeting, that idea was rejected to avoid creating panic.
The next potential step would have been Article 5: the mutual defence clause, under which an attack on one member is considered an attack on all.
That’s not on the table.
Instead, Romania has shut down a Russian consulate in the port city of Constanta as a “warning”, according to its president. Dan said the next move in the “diplomatic hierarchy of measures” would be to kick out the Russian ambassador.
But for now, he’s going nowhere.