Why did the PAIGC turn from peaceful protest to armed struggle in 1959?

The African Party for the Independence of Guinea and Cape Verde (PAIGC) initially sought to achieve independence through peaceful protest and political agitation, such as workers' strikes for better wages and conditions.12

However, the organization shifted its strategy to a rurally based armed struggle following the Pidjiguiti Massacre in August 1959. During a dockworkers' strike, Portuguese authorities responded with lethal violence, killing and wounding numerous demonstrators. This brutal suppression convinced the PAIGC leadership that peaceful means were insufficient to end the colonial regime, leading them to adopt guerrilla-style tactics and prepare for an armed campaign, which was officially launched in 1963.12