Nearly a year after the Iraqi prime minister declared victory over ISIS in Mosul, the inability of security forces to secure a major highway linking Baghdad to northern provinces is highlighting how militant sleeper cells can undermine security even as relative peace returns to much of the country.
For months an ongoing campaign of flying checkpoints, ambushes and kidnappings by militants on the highway linking the capital to the northern oil city of Kirkuk has terrorised travellers, and prompted the launch of a major military operation last week.
In the most recent incident on Saturday, two Filipina women were kidnapped by unknown men while travelling to the Kurdish capital of Erbil. In the past month at least eight members of security forces have been kidnapped and later executed by militants on the same stretch of road.
During the ferocious violence of Iraq’s 2006-2008 sectarian war, the Baghdad-Kirkuk highway was one of the most dangerous routes in Iraq, earning notoriety as the ‘Highway of Death’.
That former reputation is now resurgent say Iraqis who are forced to travel the lonely highway, which traverses remote and hard to police rural areas.
"Driving to Baghdad is getting riskier every day and we only drive during daylight because now it is impossible to drive after sunset," said Hussain, a 56-year-old taxi driver who makes daily journeys between Baghdad and Kirkuk. "We hear about more and more kidnappings and fake checkpoints by Daesh, we don't know how long it will go on like this and at what point it becomes the Highway of Death again."
Late last month, the decomposing bodies of eight Iraqis were found dumped in Salahaddin province. Days earlier the men had appeared in a video produced by ISIS demanding the release of female militant prisoners in exchange for the abductees.
The executions of the eight hostages caused a national outrage in Iraq and raised fears of an ISIS resurgence.
In response, prime Minister Haider Al Abadi ordered the immediate execution of 13 prisoners convicted of belonging to ISIS.
In a meeting with senior military officials and ministers, Mr Al Abadi said: "Our security and military forces will take forceful revenge against these terrorist cells."
He added: "We promise that we will kill or arrest those who committed this crime."
Then on Wednesday the Iraqi military launched a major joint operation to target ISIS "remnants" operating in ethnically-mixed Kirkuk, Diyala and Salahuddin provinces. Code-named "Vengeance for the Martyrs", the operation aims to coordinate military, police, militia groups and Kurdish fighters alongside international coalition air and ground forces, according to military spokesman Brig. Yahia Rasool. “It’s a vast operation to clear out the region east of the Diyala-Kirkuk" highway, he said.
As ISIS lost control of territory in the face of Iraqi military advances which culminated in the liberation of Mosul last July, surviving militant fighters went underground. "They switched to sleeper cell tactics and took refuge in the rural areas around Diyala, Kirkuk and the Hamrin mountains that are far from the outposts of government forces," a senior security source in Diyala told The National.
“The militants have shaved off their beards and wear normal civilian clothes,” said the officer, who asked to remain anonymous as he was not authorised to speak publicly. “They might be walking among the people as we speak."
The geography of the area makes it hard for security forces to track militants who use knowledge of the terrain to move freely and carry out attacks. The notorious brutality of the insurgents prevents some local villagers from cooperating with government forces.
"The terrorists have no mercy and they don't spare anyone coming their way, which makes it harder for us to gather information about their movement in such areas," the security source said.
The Hamrin mountains are a low chain of ridges extending from Diyala on the Iranian border across northern Salahaddin and southern Kirkuk provinces. ISIS militants had control over the area for more than four years and following their defeat last December have made the area their stronghold, former Iraqi colonel and Iraqi military expert Ahmad Shawqi told The National.
"Hawija was the last town to be liberated in the area, but the Hamrin mountains weren't cleared completely. ISIS militants went into hiding in the area where they had stored supplies and ammunition over the past few years," he said. "The majority of civilians from rural areas of Kirkuk and Diyala provinces are living in displacement camps and mostly they haven’t returned back to their villages. This creates a vacuum and a good opportunity for ISIS militants to move, hide and get access to their supplies saved in those areas to carry out attacks."
Complicating the security situation are tensions between Kurdish and federal forces, which both lay claim to large stretches of disputed territories in Kirkuk and Diyala. Last October those tensions culminated in limited hostilities as Iraqi forces forced Kurdish fighters to withdraw from the region.
"Unfortunately, the political dispute between Baghdad and [Kurdish] Peshmerga forces cost a lot in term of security in the disputed areas,” said Mr Shawqi. “Neither Baghdad nor Erbil should compromise the security of people in the region because of political disagreements."
The progress of the latest military operation, which includes both federal and Kurdish forces, may indicate to what extent Baghdad and Erbil have overcome those disagreements.
"The only way for Iraqi forces to prevail at this stage of the security challenges is if they can carry out strong intelligence operations, build a strong military presence in rural areas and provide enough security for villagers to return," said Mr Shawqi.