HAWI AL-AZIM -- Bullet holes riddle the concrete watchtower of a remote Iraqi army outpost north of Baghdad, a sign of an "Islamic State of Iraq and Syria" (ISIS) night-time attack that killed 11 soldiers.
The small riverside base is ringed by sand berms, a shallow moat and coils of razor wire, and three soldiers in mismatched uniforms are busy strengthening it with cement and cinder blocks.
It has been almost three years since the extremist group lost its self-proclaimed "caliphate" stretching across much of Iraq and Syria after long and gruelling battles.
But ISIS fighters remain active in a low-level insurgency and have recently stepped up their hit-and-run attacks against anyone in uniform, or anyone else who dares to stand up to them.
"They hide in holes dug into the ground or in abandoned houses," said a senior Iraqi army officer during a visit January 24 to the dusty outpost in the eastern province of Diyala.
"This is also where they hide their explosives and weapons," he told AFP during the trip, asking not to be identified.
The unenviable task of Iraq's security forces is to hunt ISIS cells in a vast territory that stretches from Baghdad to Kirkuk, almost 250km to the north, straddling three provinces.
Revenge came Saturday (January 29) when Iraqi air strikes killed nine suspected "terrorists" implicated in the deadly attack on the base.
In a statement released late Saturday, the military said it had "identified the exact whereabouts in Hawi al-Azim of the terrorist group which perpetrated this criminal act".
"Three precision strikes by Iraqi F-16s have so far killed nine terrorist elements," the statement said, adding that the mission was still underway.
The Saturday operation was only one of many such air and ground operations the Iraqi military has conducted against ISIS in recent weeks.
Coalition help as ISIS tries to reorganise
The attack on the Iraqi base and the ISIS attack on a Syrian prison last week underscore that ISIS "is trying to reorganise its troops and activities in Iraq", said Iraqi analyst Imad Allou.
A United Nations report last year estimated that about 10,000 ISIS fighters remained active across Iraq and Syria.
The ongoing ISIS presence in Syria is largely in desert hideouts in the east of the country, where the Kurds maintain a semi-autonomous administration that borders Iraq.
In Iraq, ISIS is most active in the north but has also claimed bombings of civilian targets elsewhere, including a blast last July at a market in Sadr city, a Shia suburb of Baghdad, that killed dozens.
The anti-ISIS battle has also shifted after the US-led international coalition ended its combat role in Iraq.
Its 3,500 troops, including 2,500 Americans, are limiting themselves to advising and training their Iraqi counterparts and providing indirect support.
The coalition on January 20 said it had delivered 250 pallets of propellant and artillery ammunition to Iraqi security forces "to increase its durability, survivability, and lethality".
The delivery reaffirms "our shared resolve to deal [ISIS] a lasting defeat", the coalition said on Twitter.
"In this new phase, our transformative partnership with Iraq symbolises the need for constant vigilance. ISIS is down, but not out. We will advise and assist our partner forces to enable the protection of the people of Iraq," said Maj. Gen. John W. Brennan, commander of Combined Joint Task Force - Operation Inherent Resolve (CJTF-OIR), last month.