ADEN, Yemen, Nov. 27 (Xinhua) -- At least seven activists of the pro-secession Southern Movement were arrested Tuesday as a demonstration turned violent and protesters clashed with security forces in Yemen's southern port city of Aden, witnesses told Xinhua.
The authorities tried to prevent protesters from marching on the streets and detained seven pro-secession activists, prompting clashes with the police troops in Aden's neighborhood of Sheikh Othman, the witnesses said on condition of anonymity.
Meanwhile, a security source told Xinhua anonymously that "the clashes broke out after police backed by the military raided two houses in downtown Aden. Seven members of the separatist movement were arrested during the angry demonstration."
Later in the day, separatist gunmen fired a rocket-propelled grenade at the main security headquarters in Aden's neighborhood of Mansoura, but no one was wounded, according to police officers.
North and South Yemen unified peacefully in 1990, but the relationship deteriorated in 1994. Calls for separation in the country's southern regions were renewed in 2007.
Southerners have been complaining of being marginalized, particularly since they lost the four-month civil war in 1994. Pro- secession protests have multiplied in the south amid a worsening economic situation and charges of discrimination in favor of northerners.
Concerns have increased since the conflicts in southern Yemen are creating an unstable state where al-Qaida could more freely operate to gain foothold.