After a bloody months-long, town by town push towards the Iraqi border, US-backed Kurdish forces have finally taken the last significant urban centre from ISIS, marking a milestone in the three-year fight to end the militant group’s aspiration for a caliphate.
The Syrian Democratic Forces (SDF), backed by US special forces, huge air power and cross-border artillery from Iraqi forces, have battled village by village around dusty eastern Syria’s Deir Ezzor to dislodge ISIS from their final stronghold. Although the capture of the town of Hajin marks the end of extremist’s control of Syrian population centres, ISIS fighters retreated into outlying villages and the rocky desert nearby.
Col Sean Ryan, a spokesman for the US-led Coalition, ISIS was facing its "end days." While he said the offensive against the militant group "is going very well" he said, "they still have the capability for coordinated attacks, and the fight is not over."
Some 539 SDF fighters were killed in the three-month offensive as well as 922 of the estimated 2,000 ISIS gunmen. However, some 324 civilians are also believed to have been killed in the fighting.
Over the past days, hundreds of the 15,000 civilians in the area were able to flee the enclave toward areas controlled by the SDF east of the Euphrates River and government-controlled regions on the river's west bank.
ISIS has also recently switched tactics, returning to its previous iteration as the effective terror and guerrilla group that saw it gain ground in the Syrian conflict and subsequently in a blitzkrieg takeover of swaths of Iraq.
As the offensive reached a crescendo in recent days, heavy airstrikes by US-led coalition forced ISIS fighters to withdrew south of Hajin to areas east of the Euphrates river and west of SDF positions along the border with Iraq. Among the villages still held by extremists in the enclave are Sousa, Buqaan, Shaafah, Baghouz and Shajla.
Iraqi Maj. Gen. Qassem Mohammed, in charge of operations in areas close to the Syrian border, said artillery strikes by the US-led coalition on the Iraqi side of the border targeted Hajin and areas around it.
"It is a very difficult battle," SDF spokesman Mustafa Bali told The Associated Press by phone from Syria where he said ISIS fighters are still attacking Hajin. He added that most of ISIS fighters besieged in the enclave are among the most experienced gunmen who came to the area from Iraq and Syria.
"There are still villages to be taken but Hajin was the most important as it was the base for commanders from where they directed military operations," Mr Bali said.
In recent weeks, the SDF had to draft in battle-hardened fighters from other fronts after devastating counter attacks by the extremists who used the cover of sandstorms to launch suicide bombings.
The Britain-based Syrian Observatory for Human Rights said the SDF took Hajin early in the morning, after fierce fighting under the cover of airstrikes by the US-led coalition. It said some ISIS fighters withdrew to nearby villages and that fighting is still ongoing in fields outside Hajin as SDF fighters chase out the extremists.
Europe-based activist Omar Abu Layla of the DeirEzzor 24 monitoring group confirmed that the town had been recaptured, adding that some ISIS fighters are still holed up in small pockets on the edge of Hajin.
Abu Layla said that disagreements among ISIS ranks over hierarchy between Iraqi and Syrian fighters helped "speed up the collapse" of the extremist group's defences in Hajin.
Nuri Mehmud, spokesman of the Syrian Kurdish YPG said "intense fighting" is still ongoing.
But with the liberation of the final areas held by ISIS, the question still lingers over the fate of the group's leader and founder Abu Bakr Al Baghdadi. He has not been seen in public since he announced his self-styled caliphate in 2014 from the pulpit of the famous Al-Nuri mosque in the Iraqi city of Mosul. Last month, ISIS suffered a severe blow when the SDF said it captured Osama Owayed Al Saleh, a top aide to Al Baghdadi.
There also remains the question of what happened to several high profile hostages of the terror group, among them journalist John Cantlie who was last seen in the group’s propaganda material in the city of Mosul before it was liberated.
Meanwhile, Turkish President Recep Tayyip Erdogan and his US counterpart Donald Trump have agreed to “more effective coordination” on their respective operations in Syria, after Ankara threatened to launch a new offensive against SDF units in the north-east.
The two leaders spoke after Mr Erdogan warned of a fresh Turkish operation against the Kurdish People's Protection Units (YPG), which makes up part of the SDF ranks. The move risks aggravating already strained relations between the US and Turkey, as America not only supports the SDF but has troops deployed alongside its fighters.
Mr Trump and Mr Erdogan "agreed to ensure more effective cooperation on the subject of Syria" during a telephone call, a Turkish presidential source said.
Mr Erdogan on Wednesday said he was planning a new offensive within the "next few days" east of the Euphrates River in northern Syria.
Ankara views the YPG as a "terrorist offshoot" of the Kurdistan Workers' Party (PKK), which has waged an insurgency against the Turkish state since 1984 and is considered a terror group by Ankara and its Western allies.
But the YPG has spearheaded the United States' fight against ISIS in Syria under the SFD banner.
The Pentagon has warned that any "unilateral military action into northeast Syria by any party, particularly as US personnel may be present or in the vicinity, is of grave concern".
Tensions have spiked in recent weeks after the US set up observation posts in the northeast Syria border region intended to prevent altercations between the Turkish army and the YPG.
Mr Erdogan has slammed the plan, claiming that Turkey was not being protected from terrorists but "terrorists were being protected" from possible action by Turkey.
Adding to the heated debate, a Turkish soldier was shot dead by YPG forces on Thursday in the northern Syrian region of Afrin, according to Turkey's defence ministry.
If Turkey does launch an operation east of the Euphrates, where US forces are deployed with the SDF, a point of contention will be the city of Manbij, just west of the river.
American troops are also situated in the flashpoint city, which is controlled by the YPG.
In a bid to avoid any clashes, Ankara and Washington agreed to a "roadmap" for Manbij in June which included YPG forces withdrawing from the city and joint US-Turkish patrols, which began in November.
However, as Ankara has repeatedly reminded Washington, the YPG remains in the city.
On Friday, Erdogan again urged the US to drive the Kurdish militia out of the city.
"Here is what we say: either you clean the city and [the YPG] leave, or we're going into Manbij as well," he warned.
Turkey has previously launched two operations in northern Syria. The first offensive began in August 2016 with Turkish forces supporting Syrian opposition fighters against IS and was completed by March 2017.
Then in January 2018, Turkish military forces backed Syrian rebels to clear the YPG from its enclave of Afrin.
In March, the operation was completed with the capture of Afrin city. - Additional reporting by agencies