Russian authorities and news reports say an explosion in an upscale Moscow neighborhood killed two people, including the founder of a battalion that battled Kyiv's forces in eastern Ukraine.

Since the start of Russia’s invasion, Ukraine has been accused of orchestrating a series of lethal operations on Russian territory.

Armen Sargsyan, the leader of a paramilitary unit wanted by Ukraine, died from his injuries following an explosion on Monday morning.

Two people have died after an explosion rocked an upmarket block of flats in Moscow – including the founder of a battalion that battled Kyiv’s forces in eastern Ukraine, Russian authorities and news reports said.