Russian Su-27 fighter jets (EPA)

A Russian fighter jet fired a missile near a British spy plane on September 29 patrolling over the Black Sea, according to UK Defense Minister Ben Wallace, in what appeared to be an "accident" rather than a purposeful escalation of hostilities.

"On September 29, an unarmed RAF RC-135 Rivet Joint, a civilian-style aircraft, on routine patrol over the Black Sea was interacted with by two Russian armed Su-27 fighter aircraft. It is not unusual for aircraft to be shadowed and this day was no different. During that interaction, however, it transpired that one of the Su-27 aircraft released a missile in the vicinity of the RAF Rivet Joint beyond visual range," the UK defense chief claimed.

"The total time of the interaction between the Russian aircraft and the Rivet Joint was approximately 90 minutes. The patrol completed and the aircraft returned to base," he stated.

Britain has criticized the Russian military operation in Ukraine and imposed harsh sanctions on Moscow, while providing military and humanitarian assistance to Kiev, and ties between the two nations are at an all-time low.

Wallace informed lawmakers that he had raised the government's worries about the incident to Russian Defense Minister Sergei Shoigu and that Russia had investigated and blamed it on a technical glitch.

"We don't consider this a deliberate escalation by the Russians, our analysis would concur it was a malfunction," Wallace told parliament.

"However, it is a reminder of quite how dangerous things can be when you choose to use your fighters in the manner that the Russians have done over many periods of time."

British defense chief discloses talk with Shoigu

The UK defense chief said he had discussed the air incident directly with his Russian counterpart Shoigu.

"In my letter, I made clear the aircraft was unarmed, in international airspace, and following a pre-notified flight path," he claimed.

The British defense chief said that UK patrols over the Black Sea were suspended until a response from the Russian side was received on October 10 and now flights have resumed and are escorted by fighter aircraft.

Labor's Shadow Defense Minister, Luke Pollard, called the event a "serious reminder of the necessity of avoiding escalation and miscalculation while maintaining the UK's undivided support for Ukraine."

The Russian side has not yet commented on the Black Sea air incident.