An investigation has been launched after a man was found murdered in St. Petersburg with a Christian Orthodox icon on his face.

The body was discovered in a residential block in the southwest of the city early on Thursday.

The man had numerous stab wounds to the face, and a Christian Orthodox icon was placed on it.

There was no further comment from police.

The incident comes after police in the southern city of Kazan discovered the bodies of two murdered women beneath a scrawled message calling for the release of three jailed members of the all-female punk band Pussy Riot.

The trio were jailed for two years each over a protest in Moscow's largest cathedral against the Orthodox Church's support for Vladimir Putin ahead of this March's presidential polls. The trial divided Russian society and sparked a wave of protests in support of the group.

The jailed group members' lawyer said on Twitter that the murders in Kazan were "either a horrendous provocation" or the work of a psychopath.