RC-135 Rivet Joint
A US Air Force RC-135 Rivet Joint electronic intelligence plane, a heavily modified derivative of the Boeing 707 civilian airliner. US Air Force

A U.S. Air Force spy plane had no choice but to fly into Swedish air space without permission to evade a Russian fighter jet just a day after a missile downed Malaysia Airlines Flight MH17, American military officials admitted. The plane, an RC-135 Rivet Joint, was conducting electronic surveillance on the Russian military when the Russians began tracking it with land-based radar, ultimately sending a fighter jet to intercept the plane, CNN reported.

In fleeing, the reconnaissance plane entered Swedish airspace without Sweden’s permission and may have flown over other countries without their knowledge, although military sources refused to confirm to CNN which countries might be included on that list.

“We acknowledge a U.S. aircraft veered into Swedish airspace and will take active steps to ensure we have properly communicated with Swedish authorities in advance to prevent similar issues before they arise,” the U.S. State Department told CNN in a statement Saturday.

It wasn’t immediately clear where the spy plane was flying when Russian radar tracked it; it may have been over the Baltic Sea, which would explain its flying into Swedish airspace while trying to flee from a Russian interceptor.

Russian military officials haven’t commented on the spy plane’s flight to western media, but the incident is only the latest close encounter between an American and Russian jet. In April, a Russian SU-27 Flanker fighter plane came within 100 feet of an American RC-135U reconnaissance plane over the Sea of Okhotsk between Russia and Japan.

A U.S. intelligence report, released days after the MH17 crash killed all 298 people aboard, proved while Kremlin-backed rebels are believed to have shot down the plane, American spies were almost certainly monitoring the region at the time.