In 1977, Seyoum joined the Eritrean People's Liberation Front (EPLF), which was fighting in the Eritrean War of Independence against the Haile Selassie dictatorship of Ethiopia, to which Eritrea had been forcefully annexed. After four years training as a guerilla fighter, he started training in photograph and started a joint role of fighter and war correspondent. Seyoum reported on the battle of Massawa in 1990, in which the EPLF gained control of the port city Massawa.