Yemen has arrested some 80 suspected separatists after army positions in south Yemen came under fire and shops owned by northerners were burned, an official and southern residents said on Monday. The sweeps carried out over three days followed a week of unrest in which separatists tried to block a main road linking the southern province of Lahj to the main southern city of Aden, the official said. “These people were behind acts of strife and the burning of shops in the city of al-Houta in Lahj province,” a government official told Reuters, adding that the suspects would be referred for trial. Yemen, the poorest Arab country, is battling a Shi'ite insurgency in the north as well as a resurgent al Qaeda, whose local arm claimed responsibility for a failed December bomb attack on a US-bound plane as it approached Detroit. Longstanding separatist sentiment in south Yemen has continued to simmer. Yemeni President Ali Abdullah Saleh urged Yemenis last week not to listen to secessionist calls, which he said amounted to treason. Western governments and neighbouring Saudi Arabia, the world's biggest oil exporter, fear al Qaeda is exploiting the instability in Yemen to recruit and train militants to launch attacks in the region and beyond. Tensions flared when a southern protester was killed earlier this month after police opened fire on a separatist protest. Six others were injured. Later, police clashed with demonstrators who came to claim the protester's body for burial, igniting unrest in which separatists burned northern-owned businesses last week, residents said.