Nigeria's human rights body on Thursday called on the military to launch a "thorough and prompt" investigation into what it ​called recurrent civilian casualties from military airstrikes.

The National Human Rights ‌Commission, a state body tasked with investigating alleged rights violations, said repeated reports of deaths and injuries raised serious concerns about compliance with humanitarian and human ​rights law.

Amnesty International, citing witnesses, said on Tuesday that ​at least 100 civilians had been killed in a Nigerian military ⁠airstrike on a crowded market in remote northwest Zamfara state ​last weekend, the third reported incident since April.

The military has said there ​was no evidence of civilian casualties.

Nigeria has increasingly relied on air power in conflict-affected regions, including the northeast, where it is battling a long-running insurgency, and the ​northwest, where armed kidnapping gangs known locally as bandits and Islamist ​militants operate.

The NHRC said that while the fight against insurgency, banditry and other ‌insecurity ⁠was a legitimate responsibility of the state, operations must not violate the constitution or international humanitarian principles.

"Nigerians deserve to know why this has become a recurring decimal. For how long will this continue?" NHRC ​executive secretary Tony ​Ojukwu said.

In a ⁠separate statement dated May 13, U.N. Human Rights chief Volker Turk said he was shocked by ​reports of civilian deaths in Zamfara and urged Nigerian ​authorities to ⁠undertake a "thorough, independent and impartial" investigation.

In April, about were killed in an airstrike on a weekly market in Jilli, in northeastern Nigeria. ⁠The ​military has opened an investigation into that ​incident.

Under Nigerian law, the commission can investigate alleged abuses and refer matters to the ​country's attorney general for prosecution.