The arrests were made in three districts of the coastal city on Friday, reported Ihlas news agency.

Turkey has imposed tight security ahead of the G20 meeting of heads of government next weekend in Antalya. US President Barack Obama and Russian President Vladimir Putin are among those attending and the Syrian conflict is expected to top the agenda.

Dozens of "IS" suspects have been picked up in raids across the country in recent weeks.

On Wednesday, nine alleged members of the jihadist group were picked up, amid accusations they were planning a suicide bomb attack on a political party's offices in Istanbul.

This week's arrests also follow Turkey's second election in five months on Sunday, which saw the ruling AK Party recover its parliamentary majority, which it lost in the first poll in May.

Multiple threats

Turkey intensified its hunt for IS extremists following the worst terrorist attack in the country's history when two almost simultaneous bombs were detonated at a peace rally in the capital Ankara on October 10. The attacks killed 102 people and left around 500 others wounded.

Investigators believe they have strong evidence that an IS cell in the western city of Gaziantep carried out a spate of recent bombings, including the Ankara attack.

Until recently, the country faced harsh criticism for not playing a more active role in an anti-IS coalition, which is fighting the IS jihadist movement in Iraq and Syria.

Security analysts say the militants have used entry points from Turkey into Syria to send weapons, fighters and other reinforcements.

In August, the Ankara government signed an agreement with the US to play a bigger role in the anti-IS campaign, but its participation is complicated by its own conflict with Kurdish PKK rebels.

In recent months, Turkey has renewed attacks on Kurdish fighters based along its southern border and in northern Iraq.

mm/kms (AFP, Reuters)