Denmark and Sweden are summoning Russia’s ambassadors after a Russian spy plane violated the airspace of both countries, their governments said on May 1.

Officials said the plane entered Danish airspace on the evening of April 29 east of the Danish Baltic island of Bornholm before flying into Swedish airspace.

“The Russian ambassador is summoned to the foreign ministry tomorrow,” Danish Foreign Minister Jeppe Kofod said on Twitter on May 1, referring to a “new Russian violation of Danish airspace.”

“This is completely unacceptable and particularly worrying in the current situation,” he added.

The Swedish Foreign Ministry also said the Russian ambassador would be summoned in Stockholm.

“There exist established procedures for this kind of case. It concerns notably summoning the representative of the implicated nation to the foreign ministry,” it said in an e-mail.

Swedish Defense Minister Peter Hultqvist told Swedish public radio that the violation was “unacceptable” and “unprofessional.”

In a similar incident in early March, four Russian warplanes violated Swedish airspace over the Baltic Sea.

Since the Russian invasion of Ukraine more than two months ago, there has been intense debate in Sweden, as well as in neighboring Finland, about joining NATO.

Russia has warned the EU’s two northernmost states against such a move. Denmark is already a member of the Western military alliance.

Questioned by the Dagens Nyheter newspaper, the Swedish defense minister said there was no proof that the breach was linked to current discussions on Stockholm eventually joining NATO.