A Russian military aircraft has briefly entered Swedish airspace.

The Swedish military announced on Saturday evening that the AN-30 propeller plane had initially been east of the Danish Baltic Sea island of Bornholm the night before and then flew in the direction of Swedish territory.

South of Blekinge, it violated Swedish airspace for a short time before leaving the area again.

Swedish fighter jets followed the incident and photographed the plane.

In early March, four Russian fighter jets briefly entered the airspace over Sweden.

Since the Russian invasion of Ukraine more than two months ago, there has been intensive discussion in Sweden and in neighboring Finland about possible membership of NATO.

Russia has repeatedly warned the EU's two northernmost states against such a step.

As the newspaper "Die Welt" reported, the Swedish Ministry of Defense in Stockholm condemned the incident as "completely unacceptable".

Especially in view of the "general security situation", the airspace violation was "very inappropriate", said Defense Minister Peter Hultqvist, according to the television station SVT.

"Sweden's sovereignty must always be respected." Sweden will lodge a protest through diplomatic channels.

Airspace violations also recently occurred over direct NATO territory, according to Die Welt.

As the alliance announced, there were several situations in the past four days in which Russian aircraft penetrated NATO airspace over the Baltic and Black Seas.

"Allied warplanes were on their way to pursue and intercept the Russian planes." According to Swedish media reports, both countries could possibly submit their application for NATO membership as early as mid-May.

The heads of state and government of the 30 NATO countries could then discuss this at their summit in Madrid at the end of June.