ANKARA (Reuters) - Turkish authorities detained four people in an investigation into a potential threat against British and German diplomatic missions but found no links between the suspects and any terrorist groups, the state-run Anadolu Agency said on Friday.

The investigation was prompted by intelligence about a potential Islamic State threat against the missions, Anadolu said, in a report also published by broadcaster Haberturk.

Britain's foreign office said earlier that the embassy in Ankara had been shut on Friday for unspecified security reasons. The Germany embassy said on its website that its missions were only open for limited operations after a four-day public holiday this week.

(Reporting by Tuvan Gumrukcu and Can Sezer; Writing by Nick Tattersall; Editing by David Dolan)