Qaryatain is home to 40,000 people - many of them members of Syria's

Capture of the town allows ISIS to unify several key areas under its control

Jihadis fighting for the Islamic State have seized a key town in central Syria in what is the terror group's most significant advance since capturing the ancient city of Palmyra in May.

The heavily populated town of Qaryatain lies south west of Palmyra, which is home to towering Roman ruins, and is located some 50 miles from the Assad regime-held city of Homs.

ISIS fanatics seized the town earlier this morning after three suicide bombers targeted army checkpoints at the entrance to Qaryatain yesterday.

Following intense overnight fighting, the Assad loyalists were overwhelmed - allowing the terrorists to take full control of the key town and prompting them to release a series of gloating images of militants posing with captured tanks on affiliated Facebook pages.

Terrorists: ISIS jihadis have posted a series of gloating images of militants posing with captured tanks on affiliated Facebook pages since capturing the heavily populated Syrian town of Qaryatain earlier this morning

An Islamic State fighter poses with a tank captured from Syrian regime forces during overnight clashes

Location: The heavily populated town of Qaryatain lies south west of Palmyra, which is home to towering Roman ruins, and is located some 50 miles from the Assad regime-held city of Homs

The capture of Qaryatain allows ISIS to link up areas under its control in and around Palmyra with areas in the eastern countryside of Qalamoun in Damascus province.

The UK-based Syrian Observatory for Human Rights said ISIS seized the town today after three suicide bombers targeted army checkpoints at the entrance the day before, setting off a fierce battle.

Websites affiliated with ISIS confirmed that the terror group had taken control of Qaryatain.

A Facebook page through which ISIS posts news of its military activities carried photos purportedly to show the fighting to 'liberate' the town, including a tank allegedly seized from the Syrian army.

Qaryatain lies midway between the cities of Homs, Palmyra and Damascus.

Activists say it has a mixed population of around 40,000 Sunni Muslims and Christians, as well as thousands of internally displaced people who had fled from Homs.

Taking control: ISIS fanatics (pictured) seized the town earlier this morning after three suicide bombers targeted army checkpoints at the entrance to Qaryatain yesterday

Moving in: Following intense overnight fighting, the Assad loyalists were overwhelmed - allowing the terrorists to take full control of the key town

ISIS has suffered a string of military setbacks since capturing Palmyra.

In June, Kurdish fighters and their local allies expelled the terror group from the key northern border town of Tal Abyad, cutting off a major supply route for the group.

Late last month, Turkey began carrying out airstrikes against ISIS targets in Syria.

It also agreed to allow U.S. warplanes to use the strategic Incirlik Air Base for anti-ISIS operations.

Yesterday Turkey's foreign minister said that American aircraft had started to arrive at the base, adding that an 'extensive' fight against the extremists would soon begin.

The news comes as a Kurdish official claimed that ISIS executed 19 women for refusing to have sex with its fighters.

He claimed the women were being held hostage in ISIS' Iraqi stronghold of Mosul, which the terror group seized in June last year.

Seized Qaryatain is ISIS' most significant advance since capturing the ancient city of Palmyra in May (pictured)

Until the capture of Qaryatain ISIS had suffered a string of military setbacks since seizing Palmyra (pictured)

Earlier Iran's President Hassan Rouhani told his Turkish counterpart that the two countries must work with one another to root out the threat of extremism in the Middle East.

The two countries 'should achieve a joint plan and a practical solution, with each other's help, for uprooting terrorism in the region,' Rouhani told Recep Tayyip Erdogan in a telephone call last night.

'A consolidation and expansion of ties between Tehran and Ankara is of paramount importance to us,' the official IRNA news agency quoted Rouhani as saying.

Nearly a year after a US-led coalition started air strikes against the Islamic State group, Ankara has finally launched a two-pronged offensive against the jihadis in Syria.

Turkey's strikes began two weeks ago after a series of attacks inside its territory including a devastating suicide bombing blamed on IS.

But at the same time, Turkey has also been carrying out strikes on Kurdish forces based in northern Iraq that it claims are linked to the Kurdistan Workers' Party (PKK) - a group Ankara considers a terrorist organisation.

The brave Kurdish defence forces in Syria and Iraq have so far proven to be the most effective group combating ISIS on the ground, despite little support from Western nations.