TUNIS- At least 35 migrants were killed when their boat sank off Tunisia's southern coast and 67 others were rescued by the coast guard, the Defence Ministry said on Sunday.

The rescue operation was ongoing, the ministry said in a statement. The migrants were of Tunisian and other nationalities.

Human traffickers increasingly use Tunisia as a launch pad for migrants heading to Europe as Libya’s coast guard, aided by armed groups, has tightened controls.

Security officials said the boat was packed with about 180 migrants, including 80 from other African countries.

Unemployed Tunisians and other Africans often try to depart in makeshift boats from Tunisia to Sicily in Italy.

(Reporting by Tarek Amara; Writing by Ulf Laessing Editing by Raissa Kasolowsky and Dale Hudson ) ((Ulf.Laessing@thomsonreuters.com))