UAV event in Tulcea county, Plauru area, Romania on Sun 3rd September 2023

Romania's defence minister has said that remains of a drone used in a Russian attack on a Ukrainian port have been found on Romanian territory.

His comments follow two days of him and other senior officials "categorically" denying any cross-border incident.

Ukraine had insisted it had evidence of the explosion.

Romania's president says the attack, which the defence ministry is investigating, would be a serious violation of Romania's sovereignty.

An attack on Romania, which is a member of Nato, would be "completely inadmissible", Klaus Iohannis said.

On Monday, Ukraine's foreign ministry had reported that Shahed drones "fell and detonated" in Romania on Sunday night after the latest Russian attack on the Ukrainian port of Izmail.

It called the incident further proof of the "huge threat" posed by Moscow to Ukraine's neighbours.

Now Romania's Defence Minister, Angel Tilvar, has visited the Danube Delta region close to the border with Ukraine and announced that several pieces of a drone had been found.

An investigation is now under way and the fragments are being analysed to determine whether they come from a Russian weapon.

Rebutting Kyiv's assertions became difficult after Ukraine's Foreign Minister Dmitro Kuleba announced publicly that he had photographic evidence of the incident.

He said it was "absolutely obvious" what had happened and that there was "no point in denying it".

Russia has been hitting Ukraine's port facilities along the River Danube for several weeks after pulling out of a deal to allow Ukraine to export its grain via the Black Sea.The port of Izmail, across the Danube from Romanian territory, was hit again in the early hours of Wednesday, leaving one person dead.

Odesa regional military administration head Oleh Kiper said the man killed was an agricultural worker and that port and grain facilities were damaged.

Romanian officials are not explaining their previous vehement denials of the drone incident, although the defence minister is taking the blame for "misinforming" the country's president.

The minister insisted in an interview on Romanian TV that the remains which had been found presented no threat.

He added that the authorities were on high alert and would take extra measures to secure the airspace. "We will have more observation points, more patrols."

It is not entirely clear whether the drone was shot down, and fragments landed in Romania, or whether it crashed on the Romanian side of the border.

The Romanian defence ministry previously said it had been monitoring the situation in Ukraine and on the border in real time.

"At no point did the means of attack used by the Russian Federation generate direct military threats to the national territory or the territorial waters of Romania," the ministry said in an earlier statement.