Four Yemeni soldiers and a high-ranking officer were killed in clashes with secessionist gunmen in the southern province of al-Dhalea on Tuesday, military sources told Xinhua. "Four soldiers along with an army colonel were killed during the armed confrontations with the secessionist gunmen," the local military sources said, adding that two citizens were also shot wounded. "Artillery shelling and bloody clashes have been taking place between the army and the secessionist gunmen in different areas of al-Dhalea province since the early hours of Tuesday," a local resident said. The confrontations started when a military patrol was targeted by the secessionist group, an army source said. North and South Yemen were unified peacefully in 1990, but their relationship deteriorated in 1994 and a civil war broke out. Southerners have been complaining of being marginalized, particularly since they lost the four-month war. Pro-secession protests are on the rise in the south amid a worsening economic situation and allegations of discrimination against southerners, and concerns have increased since the conflicts in southern Yemen are creating instability where al- Qaida could gain foothold.