* Militants had seized crude oil separation unit near Kirkuk
* State-run North Oil Co has lost contact with workers
* At least seven total killed in Taji bombing, Falluja shelling (Adds Kurdish recapture, death of commander)
Kurdish peshmerga forces retook a small crude oil station near the northern Iraqi city of Kirkuk which Islamic State insurgents seized earlier on Saturday, but the fate of 15 employees remained unclear.
Two officials from the state-run North Oil Co told Reuters the militants had seized a crude oil separation unit in Khabbaz on Saturday morning and said 15 oil workers were missing after the company lost contact with them.
One of the officials and a Kurdish military source said the peshmerga forces had regained control of the facility on Saturday evening and were combing it for explosives.
They were unable to confirm the fate of the 15 workers or provide details about the losses incurred by either side.
"We received a call from one of the workers saying dozens of Daesh fighters were surrounding the facility and asking workers to leave the premises. We lost contact and now the workers might be taken hostage," an engineer from the North Oil Co told Reuters, using a derogatory acronym for Islamic State.
Kurdish military sources said Major General Hussein Mansour, who had mobilised a unit from Khanaqin to reinforce the Kurdish forces outside Kirkuk, was killed by a sniper in the fighting. The mayor of Khanaqin confirmed the report.