A Russian warship has fired signal ammunition at a German helicopter that was on a reconnaissance mission over the Baltic Sea, it has been claimed.

The German Foreign Minister, Annalena Baerbock, mentioned the incident at a NATO meeting, without immediately providing further details.

Germany has been the second-biggest weapons supplier to Ukraine since the illegal invasion by Russia in 2022.

The crew of the Russian ship fired signal ammunition at the military aircraft, the German Press Agency in Brussels reported. The Bundeswehr helicopter had been on a reconnaissance flight.

It comes amid rising tensions in recent weeks between the Kremlin and NATO countries after UK and US missiles were used by Ukraine to attack Russia - leading Vladimir Putin to warn that the nations were now "directly" involved in the conflict.

The Mirror reports signal ammunition is typically only used by vessels in emergency situations. German Foreign Minister Annalena Baerbock, who confirmed the incident at a NATO conference but did not say when it took place, said many Russian ships in the Baltic Sea had been involved in circumventing sanctions.

She added that security measures surrounding undersea pipelines and data cables had been increased, and cited previous Russian attacks on infrastructure in the area.

Last month, two fibre optic cables in the Baltic Sea were damaged - one between Sweden and Lithuania, and the other between Finland and Germany.

German news site 20 Minuten also reported Ms Baerbock said attacks on cables in the Baltic Sea had caused the disruption of the global positioning system GPS.

On Monday German Chancellor Olaf Scholz visited Ukraine for the first time in more than 2 1/2 years, just weeks after he was criticised by Ukrainian President Volodymyr Zelensky for having a phone call with Russian President Putin.

That call came at a time of widespread speculation about what the new administration of President-elect Donald Trump will mean for Ukraine as the incoming president has promised to end the conflict.

In a major shift, Zelensky has signalled that an an offer of NATO membership to territory under Kyiv’s control could end “the hot stage of the war” in Ukraine.

Scholz's visit comes ahead of an early German election expected in February. As the campaign gets under way, Scholz has pointed to Germany’s status as Ukraine's second-biggest weapons supplier while also highlighting his “prudence” in working to prevent the war escalating and refusing to deliver Taurus long-range cruise missiles.