In September 1965, the first unit of six SWALA guerrillas, identified simply as ""Group 1"", departed the Kongwa refugee camp to infiltrate South West Africa. Group 1 trekked first into Angola, before crossing the border into the Caprivi Strip. Encouraged by South Africa's apparent failure to detect the initial incursion, larger insurgent groups made their own infiltration attempts in February and March 1966. The second unit, ""Group 2"", was led by Leonard Philemon Shuuya, also known by the "nom de guerre" "Castro" or "Leonard Nangolo". Group 2 apparently become lost in Angola before it was able to cross the border, and the guerrillas dispersed after an incident in which they killed two shopkeepers and a vagrant. Three were arrested by the Portuguese colonial authorities in Angola, working off tips received from local civilians. Another eight, including Shuuya, had been captured between March and May by the South African police, apparently in Kavangoland. Shuuya later resurfaced at Kongwa, claiming to have escaped his captors after his arrest. He helped plan two further incursions: a third SWALA group entered Ovamboland that July, while a fourth was scheduled to follow in September.