A Nigerian official says the militant group Boko Haram likely carried out Thursday's bombings that killed at least 31 people in the central city of Jos.
Plateau state spokesman Pam Ayuba told the French news agency (AFP) on Friday the attack was "an extension of the terrorist acts" that have hit Nigeria's states and cities.
Following Thursday's attack, emergency officials said suicide bombers driving separate cars detonated two bombs within a few minutes of each other in the Jos main market. The blasts occurred very close to where a twin car bombing in May left at least 118 people dead.
Boko Haram, which was blamed for the May attack, has been waging war for the last five years to establish an Islamist state in northeast Nigeria.
Last year, Nigerian President Goodluck Jonathan declared a state of emergency in three northeastern states.
The number of attacks has since increased sharply in the run-up to elections in February. Former military ruler Muhammadu Buhari will challenge Mr. Jonathan at the polls for a second time in next year's election.