This is according to a source in the emergency services on the scene told Reuters.
"It just happened, and our men and the security agencies are on the scene dealing with the fallout," the official said.
No one immediately claimed responsibility for the blast. But Islamist group Boko Haram has been blamed for a string of bomb attacks in trhe region this year. Gombe has rarely been attacked.
"It just happened, and our men and the security agencies are on the scene dealing with the fallout," an emergency services official told Reuters, saying five people died. The military was not immediately available for comment.
Witness Godfrey Anebo said he saw emergency services pull eight people from the wreckage, all of whom appeared to be dead.
"I am not sure what the death toll will be at the end but it will shoot up very high because the bus stop was very full of commuters," Anebo said.
The government announced a ceasefire with Boko Haram nearly two weeks ago as part of efforts to negotiate the release of more than 200 schoolgirls kidnapped by the group in April. But violence has soared since.
The militants, who have been fighting to carve out an Islamist state in the region, seized control of the northeast Nigerian town of Mubi on Wednesday and Thursday, robbing banks, burning down houses, killing dozens of people and forcing thousands to flee, witnesses said.