A Brussels Airlines plane at Brussels airport.Nicolas Economou/Getty Images A Brussels Airline flight to Cameroon had to turn back following a technical problem with the plane. About 40 passengers had to stay overnight in the airport because they didn't have Belgian visas. After further delays they began a sit-down protest blockading the international terminal. Passengers from a flight from Belgium to Cameroon that had to return to Brussels airport because of a technical problem ended up blockading the international terminal after they got stuck there overnight, Aviation24 reported.About 40 of the 273 passengers on the Brussels Airlines flight did not have a visa for Belgium, which meant they had to spend Wednesday night in the airport.The chaotic scenes began when they were told on Thursday that the next flight was fully booked, an airport spokesperson told the outlet.The passengers then began a sit-down protest that blocked access to Terminal B, which handles its international flights.