Iraqi forces launched a security operation along a planned oil transit route to Iran on Wednesday, saying it was clearing and "destroying sleeper cells" in the mountainous border area where two armed groups operate.
Iraqi oil officials announced in December plans to transport Kirkuk crude by truck to Iran's Kermanshah refinery. The trucking was to start last week and officials declined to give reasons for the delay other than it was technical in nature.
"With the goal of enforcing security and stability, destroying sleeper cells, and continuing clearing operations, an operation was launched in the early hours of this morning to search and clear areas east of Tuz Khurmato," the Iraqi armed forces said in a statement.
The operation is being conducted by the Iraqi army's 9th armored division, the interior ministry's elite Emergency Response Division, and Iran-backed militias known as the Popular Mobilization Forces (PMF), with air support from the US-led anti-Islamic State coalition and in coordination with Kurdish Peshmerga fighters, the military said.
A security official in the semi-autonomous Kurdistan Regional Government could not immediately confirm Peshmerga coordination.
Sources within the PMF said there were between 200 and 500 fighters, belonging to remnants of Islamic State and a newly emergent militant group known as the White Flags. Other security sources said the militants numbered between 500 and 1,000.