"It was a suicide bombing. Six people were killed including the bomber and 11 others were injured. We evacuated them to the hospital," Saidu Ahmed Minin, head of operation of the National Emergency Management Agency in Gombe, said.
According to eyewitnesses, the blast occurred at a time when the market was full of people.
"The bomber went into the crowd of people waiting to recharge their telephones at a public charging station and then set off the explosive. The explosion shook the whole neighborhood," taxi driver Idris Babandada told AFP.
No one has claimed responsibility for the attack so far.
With local doctors currently on strike, all those injured were treated by aid volunteers and nurses, according to a Gombe aid worker.
Gombe has repeatedly been hit by a spate of suicide bombings, most of them at bus stations and near military facilities. The attacks are thought to be the work of Boko Haram militants.