Portugal's state police force PIDE fires upon striking workers in Bissau, Portuguese Guinea, killing over 50 people.

The International and State Defense Police was a Portuguese security agency that existed during the Estado Novo regime of António de Oliveira Salazar. Formally, the main roles of the PIDE were the border, immigration and emigration control and internal and external state security. Over time, it came to be known for its secret police activities.

The Pidjiguiti massacre was an incident that took place on 3 August 1959 at the Port of Bissau's Pijiguiti docks in Bissau, Portuguese Guinea. Dock workers went on strike, seeking higher pay, but a manager called the PIDE, the Portuguese state police, who fired into the crowd, killing at least 25 people. The government blamed the revolutionary group African Party for the Independence of Guinea and Cape Verde (PAIGC), arresting several of its members. The incident caused PAIGC to abandon their campaign of nonviolent resistance, leading to the Guinea-Bissau War of Independence in 1963.

Bissau is the capital and largest city of Guinea-Bissau. As of 2015, it had a population of 492,004. Bissau is located on the Geba River estuary, off the Atlantic Ocean, and is Guinea-Bissau's largest city, major port, its administrative and military center.

Portuguese Guinea, called the Overseas Province of Guinea from 1951 until 1972 and then State of Guinea from 1972 until 1974, was a Portuguese overseas province in West Africa from 1588 until 10 September 1974, when it gained independence as Guinea-Bissau.