At its fourth session (Paris, 1-5 September 1980), the Committee elected five Vice-Chairmen including the representatives of Ghana and Yugoslavia. However, at the Third General Assembly of States Parties to the World Heritage Convention, which met in Belgrade on 7 October 1980, Ghana and Yugoslavia, whose term of office was due to expire at the end of the 21st session of the General Conference, were not candidates for re-election to the Committee and thus ceased to be members. Therefore, in accordance with Rule 12.1 of the Rules of Procedure of the Committee, these two Vice-Chairmen could no longer remain in office after the end of the 21st session of the General Conference. In consequence, at the fifth session of the Bureau (Paris, May 4-7 1981) the members of the Bureau were reduced in number.