Police arrested three people yesterday following raids on EU offices and a prestigious graduate school in a probe into suspected fraud linked to the training of future diplomats, prosecutors said.

The European Public Prosecutor's Office (EPPO) said searches were carried out at the College of Europe in the Belgian city of Bruges, and the Brussels premises of the European External Action Service -- the EU's diplomatic wing.

The raids were "part of a probe into suspected fraud related to EU-funded training for junior diplomats", said an EPPO statement, adding that "three suspects were detained."

Carried out by Belgian federal police at the EPPO's request, the searches targeted several buildings of the College of Europe and the EEAS, as well as the houses of suspects, prosecutors said.

An EU official confirmed that "raids took place" and said investigators were "looking at activities that happened under previous mandates".

The EU's current top diplomat, High Representative for Foreign Affairs Kaja Kallas, took office a year ago.