Islamic State 'declares war' on Turkey

Islamic State group militants have urged Muslims in Turkey to "conquer" Istanbul, in a video purportedly issued by the extremist organisation, Reuters has said.

The video shows a Turkish speaking fighter flanked by two armed men denouncing Turkish President Tayyip Erdogan as a "traitor" for allowing US planes to "bombard the people of Islam" and commands Turks to fight "crusaders, atheists and tyrants".

Following the bombing of Kurdish activists in Turkey, allegedly by the extremist organisation, Ankara has pursued Kurdish and IS fighters in Syria and Iraq with a number of air raids.

Six F-16 fighter jets arrived at a Turkish air base last week and began flying missions against the IS group over. 

Although the video could not be independently verified it has been shared by IS supporter on social media and resembled other propaganda distributed by the extremists.

Turkish police have clampdown on suspected IS militants and sympathisers in the past few weeks.

Ankara has been accused of turning a blind eye to IS using the Turkish border as a supply route for arms and fighters into its territory in Syria.

Police arrested four suspected IS members who were driving a car filled with weapons and a drone, today in southern Turkey.

Turkish newspaper Hurriyet reported that the men were presumably on their way to Syria.

IS have been fighting Turkish-allied Syrian rebel groups in northern Syria. Ankara is planning a 'safe zone' inside Syria, which would be run by opposition groups and free of the Islamic State group.

It could also serve as a staging post for rebels to fight the Syrian regime.

Last week, al-Nusra Front fighters withdrew from their posts in northern Syria and handed over command to opposition fighters.

Although Nusra have been on the frontline in the fight against IS, they have refused to take part in Turkey’s planned safe zone, believing it to be un-Islamic.

IS launched an initial assault on the rebel-posts near Aleppo, but have been beaten back in key areas close to the Turkish border, al-Jazeera reported.

The Levant Front is leading the charge against IS in the area, and backed by anti-IS coalition airstrikes, which have helped rebel and Kurdish militias win back territory around Tal Abyad and Kobane.