This was made known by rescue workers.
The first explosion took place outside a packed footwear shop around 1620 GMT, followed by a second explosion just minutes later, said Badamasi Amin, a local trader who counted at least three bodies.
He said the area was crowded with customers doing some last-minute shopping on the eve of the Eid festival marking the end of the Muslim fasting month of Ramadan.
“I was about 70 metres (yards) from the scene” when the first blast struck, he told AFP.
“I and many other people rushed to assist the victims. While we were trying to attend to the wounded, another blast happened outside a china shop just opposite the footwear shop.
“Several people were killed and many more were injured,” he added.
Ali Nasiru, another trader, said he saw “people lying lifeless on the ground”.
“Traders and shoppers helped in evacuating the victims to the hospital,” he said. “I can’t say how many people were affected but there are many.”
Gombe state neighbours the states of Borno, Yobo and Adamawa, which have been most affected by the Boko Haram insurgency that has killed more than 15,000 people in Nigeria since 2009.
There was no immediate claim of responsiblity for Thursday’s blasts but a market, bus station and stadium in the city of Gombe have all in recent months been targeted by bomb and suicide attacks.
Boko Haram claimed responsibility in February for an attack on Gombe during which hundreds of insurgents, armed with heavy weapons, invaded the city for a few hours.
There has been a spike in attacks by Boko Haram after a four-nation coalition of Nigeria, Niger, Chad and Cameroon pushed out the militants from captured territory earlier this year.
The violence has further intensified since Nigeria’s new President Muhammadu Buhari took power one and a half months ago and vowed to crush the group, something his predecessor had also made a priority but failed to do.
Buhari, in an Eid message, pledged to press on with efforts to quash the militants.
“I was very aware of your high expectations when I assumed office and I reassure you, my fellow citizens, that since my inauguration… I have been working with utmost dedication to meticulously plan and tackle the many national challenges which we identified and promised to resolve,” he said.
“To succeed however, I need your continued support, understanding and patience.”
Buhari, a former military man, this week sacked his entire defence top brass and told their successors that their appointments were solely based on merit.
The new chief of army staff, Major General Tukur Buratai formally took over Thursday and sidestepped questions from reporters.
“I am just a few hours on the seat,” he said.vanguard.