AFP/ Arbil

A bomb-rigged mass grave believed to hold the remains of more than 120 people killed by the Islamic State group has been found in north Iraq, an official said Saturday.

It is the sixth mass grave discovered in or near the town of Sinjar since it was recaptured from IS jihadists earlier this month, Mahma Khalil, the official responsible for the area, told AFP.

IS overran Sinjar in August 2014 and carried out a brutal campaign of massacres, enslavement and rape targeting members of the Yazidi minority, who made up most of its inhabitants.

The United Nations has described the attack on the Yazidis, whose faith IS considers heretical, as a possible genocide.

The grave site, which is estimated to contain the remains of 123 people, based on accounts from people who witnessed the executions, was surrounded by a large number of bombs, Khalil said.

Bombs are a key part of both offensive and defensive operations by IS, which overran large parts of Iraq last year.

Explosives continue to pose a major threat even after the jihadists are gone and prevent displaced residents from returning home.

The grave, located some 10 kilometres (six miles) west of Sinjar, has not yet been excavated, but the victims were not buried deeply, and some of their remains have been exposed by rainwater, Khalil said.

Another mass grave found in the area was believed to hold the bodies of some 80 women aged from 40 to around 80 who one official said may have been executed because they were deemed too old to enslave and rape.

The town of Sinjar was recaptured from IS on November 13 in a major operation led by forces from Iraq's autonomous Kurdish region, backed by air support from a US-led coalition.