The attack Saturday comes three days after Prime Minister Nouri al-Maliki declared a state of emergency in Basra after weeks of factional Shi'ite fighting.
Elsewhere in Iraq today, gunmen killed a Russian diplomat and kidnapped four Russian embassy workers in Baghdad.
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.
Separately, officials in Baquba say seven policemen were killed and at least four other people wounded in an attack at a checkpoint.
Police also say at least four bodies were found in Baghdad with signs of torture and bullet wounds.
Prime Minister 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.