Two female suicide bombers have blown themselves up at a market in north-east Nigeria's Madagali town, killing at least 30 people and wounding 67, the army said.
Boko Haram has been blamed for the attack on the edge of the Islamic extremist group's Sambisa Forest stronghold, which Nigeria's military has been bombing ahead of ground assaults.
Since the military dislodged the extremists from towns and villages this year, the insurgents have been attacking soft targets.
Survivor Ahmadu Gulak said the two explosions struck simultaneously at opposite ends of the market selling grains and vegetables.
Army spokesman Major Badere Akintoye said 30 people have died and 67 were wounded.
The seven-year Islamic uprising has killed more than 20,000 people, created 2.6 million refugees and triggered a massive humanitarian crisis.