The US-backed Syrian Democratic Forces say the Islamic State group has lost its last bit of territory in Syria, bringing to an end its “caliphate”.
A spokesman for the SDF declared the “100% territorial defeat” of IS.
The jihadist group once controlled 88,000 sq km (34,000 sq miles) of land stretching across Syria and Iraq.
Despite the loss of territory, the group is still seen as a major security threat capable of mounting attacks in the region and worldwide.
The Kurdish-led SDF alliance began its final assault on IS at the start of March, with the remaining militants holed up in the village of Baghuz in eastern Syria.
The alliance was forced to slow its offensive after it emerged that a large number of civilians were also there, sheltering in buildings, tents and tunnels.
Thousands of women and children, foreign nationals among them, fled the fighting and severe shortages to make their way to SDF-run camps for displaced persons.
Many IS fighters have also abandoned Baghuz, but those who stayed put up fierce resistance, deploying suicide bombers and car bombs.
“Syrian Democratic Forces declare total elimination of so-called caliphate and 100% territorial defeat of Isis [the IS group],” Mustafa Bali, the head of the SDF media office, tweeted.
“On this unique day, we commemorate thousands of martyrs whose efforts made the victory possible.”
SDF fighters have been raising yellow flags in Baghuz to celebrate their victory.
Why are there still concerns about IS?
IS grew out of al-Qaeda in Iraq in the aftermath of the US-led invasion of Iraq in 2003.
It joined the rebellion against Syrian President Bashar al-Assad in 2011. By 2014 it had seized swathes of land in both countries and proclaimed a “caliphate”.
The fall of Baghuz is a major moment in the campaign against IS. The Iraqi government declared victory against the militants in 2017.
But the group is far from defeated. US officials believe IS may have 15,000 to 20,000 armed adherents active in the region, many of them in sleeper cells, and that it will return to its insurgent roots while attempting to rebuild.
Even as its defeat in Baghuz was imminent, IS released a defiant audio recording purportedly from its spokesman Abu Hassan al-Muhajir, asserting that the caliphate was not finished.