The RAF has two of its jets deployed in Estonia have been scrambled twice in recent days to intercept Russian aircraft.
The RAF said the incidents brought the number of intercepts of Russian planes to eight since taking over the Baltic Air Policing mission in May.
The Typhoon jets were alerted on Friday to intercept a Russian Su-30 Flanker fighter, and passed a Russian military transport craft as it was escorting the fighter over the Baltic Sea.
On Saturday, RAF crews intercepted a Su-30 Flanker fighter and an Ilyushin Il-76 Candid transport aircraft travelling north from the Russian enclave of Kaliningrad towards Estonian and Finnish air space.
The RAF escorted the aircraft for 15 minutes before handing over responsibility to Finnish aircraft on the air space boundary.
The Russian Defence Ministry said over the weekend that its Baltic Fleet assets were monitoring Nato military drills in the Baltics.
Its statement about the interception of US bombers did not give precise locations for the incidents or say how many planes were involved.