Ukrainian soldiers claim to have shot down another Russian fighter plane, with the wreckage smouldering in a field.
According to local news agency Nexta, the Su-35S Flanker-E fighter jet, which costs £38 million, was shot down near the city of Izyum in the Kharkiv area.
According to MP Anton Gerashchenko, the pilot ejected and was apprehended as he attempted to leave.
The Russian pilot has been identified as Major Sergei Yermalov by the Ukrainian military.
He is said to be a member of the 159th Guards Fighter Aviation Regiment, which is located at Besovets airport in the Republic of Karelia in northwest Russia.
Authorities in Ukraine claim to have shot down two planes and one helicopter in the last 24 hours.