Yemeni troops shot dead a southern separatist in clashes that erupted when activists blocked roads during a protest in the main port city of Aden, medics and activists said. \"One man was killed and two others were wounded by gunfire,\" a medic at Aden\'s Al-Naqib hospital told AFP on condition of anonymity. Activists from the separatist Southern Movement confirmed the victims belonged to their group which calls for autonomy or the complete independence of the south. Aden residents said dozens of separatists took to the streets in the districts of Khor Maksar, Mualla, Sheikh Osman and Dar Saad early on Saturday, blocking roads and burning tyres, prompting clashes with the army. Residents in Mansura district spoke of \"very fierce clashes\" ongoing in their area between the army and separatists. A security official told AFP that \"supporters of the Southern Movement blocked roads and when the army tried to intervene, gunmen among them deployed in buildings in these areas opened fire on troops, prompting clashes.\" Lutfi Shatara of the Southern Movement told AFP that \"there is civil disobedience in Aden in protest against the February 21 massacre,\" referring to the killing by police of five people -- including four activists -- during pro-independence protests. Thursday\'s protests were to mark the first anniversary of the ouster of autocratic president Ali Abdullah Saleh. South Yemen broke away in 1994, sparking a civil war, before it was overrun by northern troops.