FALLUJA, Iraq (Reuters) - At least nine people were killed in Iraq’s Anbar province on Monday when gunmen attacked the home of a Sunni tribal militia officer, security sources said.

Captain Misha’an Hazemawi and eight other people were killed when gunmen stormed Hazemawi’s house near the Karma district, some 16 km (10 miles) northeast of Falluja.

No group has claimed responsibility for the attack but two security sources said Islamic State militants were behind it.

A small number of militants are still operating in the area and are capable of launching sporadic attacks, Iraqi security officials say.

The officer was a member of the Tribal Mobilisation Forces, a network of Sunni militias that backed the government in its fight against Islamic State, the security sources said.

Islamic State, which had seized control of much of northern Iraq in 2014, lost most of Anbar province to U.S.-backed Iraqi security forces supported by Sunni tribal fighters in 2016.

Iraq declared victory over Islamic State in December 2017 but security officials say the militants are likely to wage an insurgency after they were dislodged from all the territory they held.

Its fighters have kept up a campaign of kidnap and killing, mainly in the provinces of Kirkuk, Diyala and Salahuddin.