MOSCOW — Russia's Defense Ministry on Sunday denied Swedish claims that for the second time this year a Russian military aircraft had nearly collided with a passenger jet over Sweden, insisting that the two planes were never less than 70 kilometers (42 miles) apart.

Swedish officials said the Russian intelligence plane had turned off its transponders to avoid commercial radar and came dangerously close to colliding with a passenger jet that had taken off from Copenhagen on Friday.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said the military aircraft was operating in compliance with rules governing international airspace and was flying at a safe distance from routes used by civilian flights.

"There were no prerequisites for an air accident," he said in a statement carried by Russian news agencies.

Sweden's air force chief, Maj. Gen. Micael Byden, said Saturday that the incident in international air space looked "pretty serious" and the commercial flight was immediately ordered to change course, but it was not as serious as in March when a Russian plane flying without transponders came within 100 meters (300 feet) of an SAS plane that had taken off from Copenhagen.

Russia has increased its military presence in the Baltic Sea area as tensions with the West have spiked over the conflict in Ukraine. NATO also has air patrols over the Baltic Sea and rotates NATO military units in and out of member countries in the region.

Konashenkov said the number of flights by NATO warplanes along Russia's borders has tripled in recent months, and a NATO reconnaissance plane was flying between the Russian aircraft and the passenger jet on Friday. NATO aircraft also fly in international air space with their transponders switched off, he said.

Carl Bildt, the former Swedish foreign minister, said this practice should be changed. "Should we seek an agreement for all military planes in international air in Baltic area to use transponders? For transparency and safety," he wrote in a Twitter post.