Residents of Buhari village in Yunusari district near the border with Niger told AFP that 10 people were killed and at least 19 injured during air strikes on Wednesday.

The air force did not confirm or deny the alleged death toll.

"Reports reaching (the) Nigerian Air Force Headquarters alleged that some civilians were erroneously killed while others were injured," spokesman Edward Gabkwet said in a statement.

According to initial information, he said, the aircraft was "not carrying bombs".

But "a board of inquiry has been set up to thoroughly investigate the circumstances of the incident," he said.

Several residents said that three fighter jets flew over the village and one of them opened fire.

"There was an air strike by a military jet on Buhari village yesterday which left some casualties," Alhaji Bukar Gaji, a local politician said.

"We buried 10 people... and 22 were taken to the general hospital in (nearby) Geidam town," resident Grema Zanna told AFP.

Another resident, Masida Kyari, who gave a similar death toll said "three jets flew over the village and one of them opened fire."

Nigeria has been fighting a 12-year-old jihadist insurrection in the northeast that has killed more than 40,000 people and displaced nearly two million from their homes.

There have been at least two previous incidents of civilians killed in air strikes.

- 'Mistaken target'? -

Karim Modu, from an anti-jihadist militia in Geidam who was at the hospital on Wednesday, said he saw 19 people with serious injuries including "burns, fissures and fractures".

Some with more serious injuries were transferred to a hospital in the state capital Damaturu.

The air force said it had dispatched one aircraft to an area along the Nigeria/Niger border on Wednesday, "to respond to the suspected terrorist activities."

"The pilot fired some probing shots," said spokesman Gabkwet, adding, "the area is well known for continuous Boko Haram /ISWAP (Islamic State West Africa Province) activities."

The governor of Yobe state, Mai Mala Buni, said lives were lost during an air strike on Buhari village, but did not confirm a death toll.

"It could have been an accident or mistaken target, but government will join hands with the security agencies to unravel the root cause of the incident," his spokesman Mamman Mohammed said in a statement.

In January 2017 at least 112 people were killed when a fighter jet struck a camp housing 40,000 people displaced by jihadist violence in the town of Rann near the border with Cameroon.

The Nigerian military blamed "lack of appropriate marking of the area" for the bombardment in a report it issued six months later.

In July 2019 at least 13 civilians were killed when a Nigerian fighter jet hit Gajiganna village, as it targeted fleeing jihadists who had attacked a nearby base.