MEP Ivaylo Valchev has written to the European External Action Service (EEAS) after Serbia refused entry to representatives of the Western Outlands Scientific Institute, his office said.
On 10 October, Serbian authorities turned back Assoc. Prof. Angel Dzhonev, the institute's chairman, and handed him an official entry ban. He received the document at the Ribarci border checkpoint. It gives "a threat to national security" as the reason.
Dzhonev told BTA about the refusal. He was travelling to take part in events marking 28 years since the founding of the Bosilegrad Cultural and Information Centre.
In August, a similar ban was imposed on Dr Valentin Yanev, a member of the institute's management board. The details of both cases come from a press release by the Bulgarian MEP's office.
Valchev wants the EEAS to raise the cases with the Serbian authorities and ask them to explain exactly why they imposed the bans. He urged the service to act within its powers.
The MEP said the cases raise serious questions about freedom of expression, academic freedom and protection from discrimination. They also affect the right of the Bulgarian community in Serbia to keep its national and cultural identity.
"Protecting the rights of Bulgarians in the Western Outlands must not remain just a declaration," Valchev said. He said respect for basic rights and protection of national minorities must be a real commitment in relations between the EU and Serbia, especially as Serbia moves towards EU membership.