The Tunisian Writers Union decried on Monday Egypt’s refusal to allow the entry of researcher and academician Amel Grami at Cairo International Airport, and sending her on a plane back to Tunisia.

The union called on the Egyptian authorities to issue a formal apology to Grami.

Grami was heading to the coastal City of Alexandria on Saturday to attend a conference on terrorism and extremism in the Bibliotecha Alexandrina. She told the Tunis 24/7 TV Show that she had obtained a visa three months prior to her arrival.

She added that Egyptian authorities kept treating her as a "detainee," and questioning her for over 10 hours.

Egyptian authorities have not commented on the incident.

This is not the first high-profile incident where Egypt denied entry to foreigners.

In December 2014, airport authorities denied entry to Michele Dunne, a senior associate in the Middle East Programme of the Carnegie Endowment for International Peace and a former US diplomat, who received an invitation by a pro-government group to attend a conference.

Authorities said at the time that Dunne did not have a valid visa.