Sanaa, Dec 15 (IANS): A pro-secession leader was shot dead by Yemeni security forces in the southern port city of Aden on Monday, a witness told Xinhua.

"Security forces opened heavy gunfire on a small pick-up truck carrying activists of the secessionist movement in Aden's neighbourhood of Cerater, killing a pro-secession leader," said the witness, Ahmed Basha.

A security official in Aden confirmed the killing, saying that soldiers opened fire after the vehicle that the leader was riding refused to stop at a security checkpoint.

Just a few hours after the incident, supporters of the pro-secession southern movement, which demands independence, called for "Protests of Rage" across the Aden province.

About five people were injured when Yemeni security forces fired live ammunition and teargas at a separatist rally in Aden city Monday, according to medics.

North and South Yemen unified peacefully in 1990, but their relationship deteriorated in 1994. Calls for separation in the country's southern regions were renewed in 2007.

The southerners have been complaining of being marginalised, particularly since they lost a four-month civil war in 1994.

Pro-secession protests are on the rise in the south amid a worsening economic situation and allegations of discrimination in favour of the northerners.

Concerns have grown since the conflicts in south Yemen are creating instability where the Al Qaeda could gain foothold.