he received military training in tanganyika and later algeria. he was one of the founding members of the south west african liberation army (swala), which eventually transformed into swapo's armed wing of plan. in 1966, mnyika was captured during the battle at omugulugwombashe, the first military conflict of the namibian war of independence against south africa. in february 1968, he was convicted on terrorism-related charges by the occupying apartheid officials from south africa and sentenced to life in prison. he was sent to robben island and spent 17 years in prison. he was released from prison in 1985 and returned to namibia, only to go back into exile in 1988. he returned to namibia in 1989 ahead of the 1989 election and independence of namibia.