The Russian Foreign Ministry confirms that a Russian diplomat has been killed and four embassy workers kidnapped in Baghdad.
Iraqi officials say gunmen Saturday attacked the group in the Mansour neighborhood of Baghdad, not far from the Russian embassy.
Police also say at least four bodies were found across the capital with signs of torture and bullet wounds.
Separately, officials in Baquba say seven policemen were killed and at least four other people wounded in an attack at a checkpoint.
Authorities also say eight severed heads were found near Baquba, north of Baghdad. A note left at the scene identified one of the victims, and accused him of killing Shi'ites.
Prime Minister Nouri al-Maliki on Sunday is expected to announce the names of candidates for the defense and interior ministers. The two positions are key in efforts to help improve the country's security amid the raging violence.