Midjiyawa Bakari, governor of the far northern region of Cameroon, told The Associated Press that the attacker detonated the explosives in the popular Pont Vert neighborhood in Maroua.
"We are still counting the dead and wounded," Bakari said by phone lasy night.
While there was no immediate claim of responsibility, Islamic militants from the Boko Haram group have been blamed for scores of attacks in the region this year.
Troops from Cameroon and Chad are fighting Islamic extremists in several communities on Cameroon's border with Nigeria. Cameroon has arrested dozens accused of promoting radical ideology and collaborating with Boko Haram.
On Wednesday, at least 20 people were killed in Maroua when two suicide bombers blew themselves up in a busy marketplace and a popular neighborhood. Authorities later said one of the bombers was a 9-year-old girl who had been disguised as a beggar.