December, around 80 policemen died. The major part of the freedom fighters of Azad Gomantak Dal were not Goans. Many had fought in the British Army, under General Montgomery, against the Germans." Diplomatic efforts to resolve Goa dispute On 27 February 1950, the Government of India asked the Portuguese government to open negotiations about the future of Portuguese colonies in India. Portugal asserted that its territory on the Indian subcontinent was not a colony but part of metropolitan Portugal and hence its transfer was non-negotiable, and that India had no rights to this territory because the Republic of India did not exist at the time when Goa came under Portuguese rule. When the Portuguese government refused to respond to subsequent aide-mémoires in this regard, the Indian government, on 11 June 1953, withdrew its diplomatic mission from Lisbon. By 1954, the Republic of India instituted visa restrictions on travel from Goa to India which paralysed transport between Goa and other exclaves like Daman, Diu, Dadra and Nagar Haveli. In the same year, India instituted sanctions on Portugal with the aim of the annexation of Goa into India, the sanction would remain until 1961. Meanwhile, the Indian Union of Dockers had, in 1954, instituted a boycott on shipping to Portuguese India. Between 22 July and 2 August 1954, armed activists attacked and forced the surrender of Portuguese forces stationed in Dadra and Nagar Haveli. On 15 August 1955, 3000–5000 unarmed Indian activists attempted to enter Goa at six locations and were violently repulsed by Portuguese police officers, resulting in the deaths of between 21 and 30 people. The news of the incident built public opinion in India against the presence of the Portuguese in Goa. On 1 September 1955, India shut its consul office in Goa. In 1956, the Portuguese ambassador to France, Marcello Mathias, along with Portuguese Prime Minister António de Oliveira Salazar, argued in favour of a referendum in Goa to determine its future. This proposal was however rejected by the Ministers for Defence and Foreign Affairs. The demand for a referendum was repeated by presidential candidate General Humberto Delgado in 1957. Prime Minister Salazar, alarmed by India's hinted threats at armed action against Portugal's presence in Goa, first asked the United Kingdom to mediate, then protested through Brazil and eventually asked the United Nations Security Council to intervene. Mexico offered the Indian government its influence in Latin America to