Turkish police have arrested 21 people suspected of being members of Isis, according to state media reports.
Authorities seized hunting rifles and ammunition in the simultaneous operations which took place at dawn.
It is reported that police seized nine firearms as well as homemade explosives in the raids.
Three of the detainees were foreign nationals, who authorities believe were planning on entering Syria to fight for the militant group.
Nato has been putting pressure on Turkey to do more to prevent foreign fights from crossing into Syria to join Isis.
US officials held talks in the Turkish capital of Ankara this week on how the country can crackdown on Isis activity.
Turkey and Syria share a border which is around 400km long.
Earlier this month it was reported that a family of 12 from Luton travelled to Syria after going missing in Turkey.
A community leader in Luton said there were suggestions that at least one member of the family had been “radicalised”. The party initially travelled to Bangladesh from Heathrow via Istanbul on 10 April, before flying back to the Turkish city on 11 May. They were due to come back to London three days later. However, they did not appear. They were last spotted in Istanbul and later released a statement online stating that they had entered Syria and joined Isis.Reuse content