Four people allegedly planning attacks on the British and German embassies in Ankara were arrested by Turkish police, state media reported.
Authorities said the suspects had no known links to Islamist militant groups, state media agency Anadolu reported. Three of the suspects were detained in Ankara and one in Istanbul, it reported.
It comes after the British Embassy in Ankara is closed today (16 September) over fears of an attack on the first Friday after Eid al-Adha.
The Foreign & Commonwealth Office said in a statement the embassy in the Turkish capital would be closed for security reasons and has continued to advise against all travel within the proximity of Turkey's border with Syria.
"The Foreign & Commonwealth Office (FCO) advise against all travel to within 10km of the border with Syria and to the city of Diyarbakir," the ministry said in a statement.
Turkey has been rocked by instability in the wake of a failed coup in July which attempted to unseat Turkish President Recep Tayyip Erdogan and his ruling AKP party.
Thousands have been arrested in the wake of the failed military putsch which the Turkish government has blamed on opposition cleric in exile Fethullah Gulen.
Germany temporarily closed its embassy, consular officers and a school on Wednesday amid reports of the possibility of attacks during the Muslim festival of Eid al-Adha, the Press Association reported.
A suicide bomber at a wedding in the southeastern city of Gaziantep last month killed more than 50 people, including 22 children. The attack is believed to have been carried out by Islamic State.
It was the deadliest terror attack in Turkey so far this year.