During the period of uncertainty in Djibouti, the Duke of Aosta urged an attack on British Somaliland in order to cut off the French colony from British support. Benito Mussolini approved the campaign on 19 July, but the situation in Djibouti changed rapidly in Italy's favour after that. The 17th Colonial Brigade under Colonel Agosti occupied the French fort at Loyada on the border with British Somaliland in early August. When the Italian invasion of British Somaliland began on 3 August, the forces at Loyada moved on Zeila, which they had taken by 5 August. The French territory was completely surrounded on land by Italian possessions. Vichy managed to continue supplying it by submarine from Madagascar, and maintained direct contact by air through flights from France via Greece (usually terminating in Madagascar).