Denmark and Russia traded accusations on Tuesday after Danish authorities said a Russian frigate fired two flares toward a Danish military helicopter operating over international waters near the Danish island of Gedser.

Denmark’s armed forces said the incident occurred on Monday during a routine photographic operation involving one of the air force’s Fennec helicopters.

The frigate, which was in international waters, fired two flares toward the helicopter, one of which passed close to the aircraft, the armed forces said.

Danish Prime Minister Mette Frederiksen described the incident as “reckless action from Russia”, accusing Moscow of seeking to intimidate and divide.

“Russian actions are meant to intimidate and divide. They will not succeed. We will not waver,” Frederiksen said on social media.

Russia rejected Denmark’s account. Russian Ambassador to Denmark Vladimir Barbin said the helicopter had engaged in what he described as provocative and potentially dangerous manoeuvres near the Russian vessel.

“Attempts to explain the helicopter’s provocative actions against the Russian frigate as ‘routine practice’ give rise to serious concern,” Barbin said in a statement cited by AFP.

He said Russia would investigate the circumstances of the incident and claimed it was not the first time Danish military helicopters had conducted what Moscow considered dangerous manoeuvres near Russian warships outside Danish territorial waters.

Barbin also said he had raised similar concerns with Denmark’s foreign ministry last year after a Danish Air Force helicopter allegedly conducted low-altitude flights and hovered over a Russian anti-submarine vessel.

The competing accounts come as military activity and surveillance operations involving Russia and NATO members have increased across northern Europe following Russia’s invasion of Ukraine.

The incident could add to tensions between Copenhagen and Moscow, particularly as Denmark has been among the European countries supporting Ukraine and strengthening security cooperation with NATO allies.

Neither side has publicly provided independent evidence establishing whether the flares were intended as a warning, defensive measure or an attempt to interfere with the Danish helicopter.

The dispute therefore remains centred on competing accounts of what happened during the encounter, with Denmark describing the Russian action as reckless and Moscow portraying the Danish aircraft’s operation as provocative.