Twin blasts have rocked a market in the northeast Nigerian city of Gombe, leaving 30 people dead, witnesses said.
"I have 30 bodies in bags and I am sure there are more out there," said a Red Cross official, who was involved in the evacuation and wanted to remain anonymous.
An official from the National Emergency Management Agency also confirmed that the attacks had taken place and many people were hurt.
Al Jazeera's Yvonne Ndege, reporting from the capital Abuja, quoted witnesses as saying that "there was an incredible amount of panic" at the market following the attack.
She also reported that at least two suicide bombers were involved in the attack.
No one has claimed responsibility for the blasts, which went off around 16:30 GMT, but they bore the hallmarks of attacks by Boko Haram.
The armed group have killed thousands in a six-year insurgency in the country's northeast.
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 from the scene" when the first blast struck, Badamasi Amin, a local trader, 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.
Gombe's market and bus station have in recent months been targeted by bomb and suicide attacks.
President Muhammadu Buhari has made crushing the armed group his top priority, but hundreds have been killed in bombings and shootings since he was inaugurated on May 29.
Buhari is set to travel to the United States, where he is scheduled to meet President Barack Obama on Monday.
Source: Al Jazeera and agencies