Reuters reported that a drone launched by Russia during an attack on Ukraine hit a residential building in the eastern Romanian city of Galați.
Romanian authorities said the incident caused a fire in the building and injured at least two people.
Romania is a member of both the European Union and NATO.
The President of the European Commission said that Russia had crossed a red line with the strike, while a NATO spokesperson condemned the incident.
The Russian government has not yet commented on the matter.
