Militants of the Islamic State group killed over 40 people on Wednesday, including Iraqi army soldiers, in a city captured earlier in October, according to media reports. The execution-style killings reportedly took place in the city of Hit in the western Iraqi province of Anbar, about 85 miles west of Baghdad.

The Islamic State group targeted members of the Sunni Albu Nimr tribe, which had fought against them in Anbar, according to media reports. Of the 46 people killed, 40 belonged to the tribe. Tribal leaders reportedly blamed the Iraqi government, led by Haider al-Abadi, a Shia, for the massacre.

“We requested many times from the security commanders, the Iraqi government, and other security leaders to provide us with arms to fight Islamic State but nobody listened to us until what happened today,” Sheik Ghazi Faisal Al-Gu’od, a member of parliament and an Albu Nimr leader, said, according to a report by The Wall Street Journal.

According to Human Rights Watch, ISIS militants have reportedly executed nearly 700 people, mostly captured soldiers, in the western provinces of Iraq so far. However, this is believed to be the first such mass killing of civilians in Anbar province, 80 percent of which is under ISIS control, according to media reports.

Following Wednesday’s executions, distrust among Sunni tribes for the government in predominantly Shia Iraq is expected to grow, and make them more sympathetic to militant groups like ISIS.

The country's moderate Sunni population, which deeply disliked the Nouri al-Maliki government, is reportedly yet to warm up to the new government despite the violent actions of the Sunni ISIS. This makes defending towns and villages in the western provinces of Iraq much more difficult as the country’s army depends to a large extent on tribal fighters to fend off attacks from the Islamic State group.