ABUJA, Nigeria (AP) — At least 85 people have been confirmed dead after a “mistaken” army drone attack on a religious gathering in northwest Nigeria, authorities said. The president on Tuesday ordered a probe into the latest in a series of mistakes in Nigeria’s conflict zones.

“Eighty-five dead bodies have so far been buried while (a) search is still ongoing,” Nigeria’s National Emergency Management Agency (NEMA) said in a statement that listed children, women and the elderly among the victims. At least 66 people were injured, the agency added.

Since 2017, some 400 civilians have been killed by airstrikes the military said were targeting armed groups in the deadly security crisis in the country’s north, according to the Lagos-based SBM Intelligence security firm.

The victims in the latest incident were observing the Muslim holiday celebrating the birthday of the Prophet Muhammad, Mawlid al-Nabi. They were killed Sunday night by drones “targeting terrorists and bandits” in Kaduna state’s Tudun Biri village, according to government and security officials.

“The incidence of miscalculated airstrikes is assuming a worrisome dimension in the country,” said Atiku Abubakar, Nigeria’s former vice-president and the main opposition presidential candidate in this year’s election.

Nigeria’s military often conducts air raids as it fights the extremist violence and rebel attacks that have destabilized Nigeria’s north for more than a decade, often leaving civilian casualties in its wake, including in January when dozens were killed in Nasarawa state and in December 2022 when dozens also died in Zamfara state.

“Terrorists often deliberately embed themselves within civilian population centers,” Maj. General Edward Buba, spokesman for Nigeria’s Defense Headquarters, said Tuesday in a statement on the latest incident.

Analysts have in the past raised concerns about the lack of collaboration among Nigerian security agencies as well as the absence of due diligence in some of their special operations in conflict zones.

One major concern has been the proliferation of drones within Nigerian security agencies such that “there is no guiding principle one when these can be used,” according to Kabir Adamu, the founder of Beacon Consulting, a security firm based in Nigeria’s capital, Abuja.

Nigerian President Bola Tinubu ordered “a thorough and full-fledged investigation into the incident.” However, such investigations are often shrouded in secrecy and their outcomes are never known.

“The military sees itself as a little bit over and above civilian accountability as it were,” Adamu said.

In the incident in Nasarawa in January, when 39 people were killed, the Nigerian air force “provided little information and no justice” over the incident, Human Rights Watch said.

Such incidents are facilitated by the lack of punishment for erring officers or agencies, according to Isa Sanusi, Amnesty International’s director in Nigeria.

“The Nigerian military is taking lightly the lack of consequences … and the civilians they are supposed to protect are the ones paying the price of their incompetence and lack of due diligence,” Sanusi told The Associated Press.