Islamic State in Iraq and Syria (ISIS) has claimed responsibility for an attack on the convoy of Governor Kashim Shettima of Borno State near the town of Dikwa on Tuesday.
The group, in a statement on its Amaq news agency, said that 42 people were killed in the attack on the Borno governor.
Concise News had reported that a Boko Haram attack on a convoy of vehicles carrying Shettima had left four people dead and an unknown number of others kidnapped.
Shettima was travelling with the governorship candidate of the All Progressives Congress (APC), Babagana Umaru.
Both escaped unhurt and were able to continue to Gamboru, where they spent the night before returning to the state capital, Maiduguri, on Wednesday.
Official sources told Reuters earlier on Wednesday that between three and 10 people were killed, and that some of them may have been beheaded.
Security sources said the gunmen opened fire at the motorcade transporting Shettima on his way from state capital Maiduguri to the market town of Gamboru for a rally.
Two security sources said three people died. A government and a separate security source said as many as 10 people were killed. Some of those killed may have been beheaded, they said.
There was no indication of how Shettima was affected by the attack.
His spokesman could not be reached for comment. A security source said the convoy had returned to Maiduguri.
Boko Haram has waged a decade-long insurgency in Nigeria’s northeast which has killed around 30,000 people and forced about 2 million to leave their homes.