At least 100 civilians were killed in a Nigerian military airstrike on a crowded market in northwest ​Zamfara state, Amnesty International said on Tuesday, urging authorities to ‌open an immediate investigation.

The airstrike, which hit the remote Tumfa market in Zurmi district on Sunday, was the second to kill scores of people at a ​crowded market in northern Nigeria in a month.

In April, around 200 civilians were killed in a similar airstrike on ‌a ⁠weekly market in Jilli, in northeastern Nigeria. The military has opened a probe into that incident.