Liberated: Syrian forces declare ISIL's last Syrian stronghold clear of militants

ISIL militants on Thursday withdrew from their last stronghold in Syria, a strategic town near the border with Iraq, following a government offensive that has effectively left their fighters dispersed in villages and small towns in the desert.

The Syrian military declared the town liberated after intense battles that killed a large number of militants, including leaders. The military said they are still pursuing other militants in different directions in the desert.

"The liberation of Boukamal is of great importance because it is a declaration of the fall of this group's project in the region generally and the collapse of its supporters' illusions to divide it, control large parts of the Syria-Iraq borders and secure supply routes between the two countries," said army spokesman Gen. Ali Mayhoub in a televised statement.

Syrian pro-government media said Syrian troops had clashed with remnants of ISIL in the town after they entered it late on Wednesday. On Thursday, they reported the town clear of ISIL fighters.

Pro-Syrian media reported the town was liberated. Broadcasting from the road into the town, Al-Ikhbariya TV, joyfully declared,  "Daesh is finished. Live."

The  Syrian Observatory for Human Rights, the war monitor based in Britain,  said government forces and allied troops were combing through Boukamal after the withdrawal of ISIL. The allied troops include Iraqi forces who linked up with the Syrians from across the border.

With their collapse in Boukamal, ISIL militants have no major territorial control in Syria and Iraq and are believed to have dispersed into the desert west and east of the Euphrates River. American officials have estimated that there were between 2,500 and 3,500 militants around Boukamal, including some of their leaders who are believed to have taken refuge there.

ISIL has suffered consecutive defeats at the hands of separate but simultaneous offensives in Iraq and Syria by the Russian-backed Syrian forces and allied militias as well as US-backed Iraqi and Syrian fighters. However, the group's media apparatus has remained active and its fighters are likely to keep up their insurgency from desert areas.

The swift fall of Boukamal in eastern Deir Ezzor province was accelerated after Iraqi forces seized Qaim, the town across the border last weekend, also controlling a strategic crossing between the two countries.

A senior Iraqi official said there was an agreement on Tuesday to send Iraqi paramilitaries to Syria to take part in the Boukamal operation, with the Syrians supplying weapons and gear.

An Iraqi spokesman for the Popular Mobilization Forces last week said his men, who are part of Iraqi security forces, would participate in the operation and head north to protect the borders and secure the road from Iran to Lebanon.

Boukamal was the last urban centre in militant hands in both Iraq and Syria. Syrian troops —backed by Russia and Iranian-supported militias — and American-backed Syrian Democratic Forces (SDF) are vying for control of the strategic border town.It was not clear if the government seizure of the town means the end of the race for control of territory previously held by ISIL.

Washington is wary of increasing Iranian influence in the area and has backed the SDF in their bid to uproot ISIL from the Syria-Iraq border areas.   The proximity of the different forces to each other raises concerns about potential clashes between them as they approach Boukamal from opposite sides of the Euphrates River, and now from across the border with Iraq.

So far the Kurdish-led SDF have focused on the area east of the Euphrates, seizing a number of oil and gas fields and securing large swathes of territory along the border with Iraq, as well as the newly liberated Raqqa city.

Meanwhile across another border, in Turkey, police on Thursday detained at least 111 suspected ISIL militants in raids on around 250 addresses in the capital, Ankara. The authorities had arrest warrants for a total of 245 people, suggesting the operation - which involves 1,500 anti-terrorist and intelligence personnel — to detain other suspects continues.

The Anadolu Agency said some of the suspects were members of a local group that allegedly "sponsored" ISIL.