A pre-flight briefing of the Nigerian Air force pilots By Ahmed Kingimi and Adewale Kolawole
The Nigerian Air Force, responding to reports of civilian casualties, said in a statement it had activated its Civilian Harm Accident and Investigation Cell "to immediately proceed to the location on a fact-finding mission on the allegation".
Earlier, the Air Force said it had killed Boko Haram militants in the Jilli axis in Borno state.
The government of neighbouring Yobe state later said in a statement that an air strike on the area had been conducted near a market where shoppers and vendors had gathered.
"Some people from Geidam LGA (local government area) bordering Gubio LGA in Borno state who went to the Jilli weekly market were affected," said Brigadier General Dahiru Abdulsalam, military adviser to the Yobe state government.
He gave no further details.
'A VERY DEVASTATING INCIDENT'
The strike occurred in a village in Yobe on the border with Borno, the heartland of a long-running insurgency that has killed thousands of people and displaced millions more.
Lawan Zanna Nur Geidam, the councillor and traditional head of Fuchimeram ward in Yobe's Geidam district, told Reuters that those injured were being taken to hospitals in Yobe and Borno.
"It's a very devastating incident at Jilli Market. As I'm speaking to you, over 200 people have lost their lives from the air strike at the market," he said in a telephone interview.
Three other residents and an official from an international humanitarian agency confirmed the strike and the estimated death toll.
The Yobe State Emergency Management Agency said it had received preliminary reports of an incident at Jilli Market "which reportedly resulted in casualties affecting some marketers" and activated emergency response.
Ahmed Ali, a 43-year-old resident who sells medical consumables at the market, said he had been injured in a blast.
"I became so scared and attempted to run away, but a friend dragged me and we all lay on the ground," he said from hospital.
(Reporting by Ahmed Kingimi and Adewale Kolawole in Maiduguri, Hamza Ibrahim in Kano and Camillus Eboh in Abuja; Writing by MacDonald Dzirutwe; Editing by Tim Cocks, David Goodman and Alexander Smith)