"We've registered eight deaths at the site, including the suicide bomber," a regional security source said without saying if the attack on a food stall was carried out by a man or a woman.
A source close to regional authorities also confirmed the attack to AFP and put the toll at eight dead, including the attacker.
It was the second time that Kolofata, which is regularly targeted in attacks blamed on Boko Haram, has been hit by a suicide attacker. At least seven were killed there in a double suicide attack on September 13.
Cameroon, Chad and Niger have formed a military alliance with Nigeria and Benin to battle the extremists, who this year declared allegiance to the Islamic State.
The Islamists' grip on the region has suffered as a result of offensives launched by local armies.