"Between 10 and 15 Islamic State group fighters attacked this federal police forward position around 12:30 am (2130 GMT Tuesday). The attack lasted around an hour," the source said, asking not to be identified.

The attackers struck near the village of Al-Jillam in an area 140 kilometres (90 miles) north of Baghdad where jihadists remain active.

IS established a so-called caliphate across swathes of Syria and Iraq from 2014.

It was defeated in Iraq in 2017 after offensives by Iraqi forces with the support of the US-led coalition that has included more than 80 countries, among them Britain, France and several Arab nations.

Even though Iraq declared victory against the IS jihadists in December 2017, the group's remnants still carry out sporadic attacks against security forces, particularly in sparsely populated desert or mountain areas.

The last major attack claimed by the Sunni extremists came in July last year, when they bombed a market in the Baghdad Shiite district of Sadr City.

The US-led coalition formed to fight IS formally ended its combat mission in Iraq in December, shifting to a training and advisory role.

The 2,500 US and 1,000 other coalition troops had been acting as advisers and trainers since mid-2020.