The United Nations (UN)  has called for independent investigations into separate airstrikes by the militaries of Nigeria and Chad after reports that dozens of civilians were killed in northern Nigeria.

According to Channels Television, citing AFP, UN High Commissioner for Human Rights Volker Turk said on Wednesday that both countries must launch “prompt, thorough, independent and impartial investigations” into the incidents.

The call followed reports that Nigerian military airstrikes struck a market in Zamfara State on Sunday, with Amnesty International saying at least 100 civilians were killed. A resident quoted by AFP placed the death toll at 117.

Turk said he was “shocked” by the reports and urged Nigerian authorities to ensure accountability if violations of international law were confirmed.

He also expressed concern over attacks carried out by Chadian fighter jets against camps linked to Boko Haram on islands in the Lake Chad region. Reports said dozens of Nigerian fishermen working in areas under militant control were among those killed.

The affected islands lie within the Lake Chad basin, shared by Cameroon, Niger, Nigeria and Chad. Footage seen by AFP showed injured fishermen receiving treatment at a hospital in Bosso, Niger.

Turk said both militaries must take all feasible precautions to protect civilians during operations against Boko Haram and Islamic State West Africa Province.

He stressed that military operations must comply fully with international humanitarian and human rights law, adding that civilians and civilian infrastructure must never be targeted.