Three members of a pro-government militia were injured in a suicide bombing in Iraq’s oil-rich Kirkuk province on Sunday, according to a local police officer.

A bomber blew himself up near a headquarters of the Shia Hashd al-Shaabi militia in central Kirkuk, Capt. Hamed al-Obaidi told.

He said three militia members were injured in the attack.

No group has yet claimed responsibility for the bombing, which came hours after two police officers were killed in an attack on an oilfield in southwestern Kirkuk on Saturday.

Last December, officials in Baghdad declared that Daesh’s military presence in Iraq had been all but dismantled.

Nevertheless, it appears that the group still maintains “sleeper cells” in several parts of the country, including Kirkuk.