The Rudaw news agency reported that improvised explosive devises, planted on the two buses, went off in two Kirkuk’s districts on Thursday.
While no group has claimed responsibility for the attack, the local authorities blamed it on the remnants of the Daesh* terror group, according to Rudaw.
"Kirkuk Provincial Council, while strongly condemning this cowardly terrorist attack... renews its insistence on the necessity to uproot the roots of terror and strike with an iron fist against ISIS remnants, not underestimate them, and for the security forces to take the highest degree of alertness and carefulness," the council said in a statement late on Thursday.
Daesh was defeated in Iraq in late 2017. However, some terror cells are still believed to be operating in the country.
*Daesh (ISIL/ISIS/Islamic State/IS), a terrorist group banned in Russia and a wide number of other countries.