Turkish President Recep Tayyip Erdogan vowed Ankara would continue to purchase oil and natural gas from Iran despite US sanctions in comments published on Friday.

Five people were injured Wednesday when a roadside bomb exploded as a bus carrying police drove by in the southern Turkish province of Adana, state media reported.

Turkish President Recep Tayyip Erdogan will host his Russian and Iranian counterparts on Monday for their latest summit on Syria, with attention focused on Damascus's push on the last rebel-held bastion of Idlib.

Former Turkish prime minister Ahmet Davutoglu on Friday said he would launch a "new political movement" in the latest challenge to President Recep Tayyip Erdogan from his former allies.

Syrian soldier Ahmad Amuri rolls up on a motorbike to hand water bottles to comrades standing guard under pistachio trees, just a few dozen metres from a Turkish observation point in northwest Syria.

Ankara will not tolerate any delay from the US over setting up a safe zone in northern Syria, Turkey's foreign minister said on Thursday.

Still reeling from his sudden deportation from Turkey with just the clothes on his back, Mohammad Hassan stood in the arrivals hall at a border crossing in northern Syria unsure what to do next.

The warnings were unambiguous, and now so is the retreat: after threatening to hit Turkey with sanctions for buying a Russian missile defense system, the Trump administration is looking for a way to avoid doing so.

The death toll from Wednesday's  attack on Turkish consular employees in Iraq's autonomous Kurdish region has risen to three after one victim died of his wounds, his family told AFP.

Turkish police began nationwide raids Tuesday aimed at detaining over 200 military personnel suspected of ties to the group blamed for a 2016 coup attempt, officials and state media reported, in an ongoing crackdown that has seen thousands jailed.