Three Yemeni soldiers were killed by unknown gunmen in an attack in southern province of Shabwa on Sunday, pan-Arab al-Jazeera TV reported.
The attack took place at a checkpoint of the province by some unknown assailants suspected to belong to the southern movement, Xinhua reported.
There has been repeated clashes in southern Yemen between separatists and government forces as the southerners accuse the government of leaning toward the northerners and being indifferent to their problems, especially in regard to the development process.
Northern and southern Yemen were unified in 1990 according to a deal between the People's General Congress and the Yemeni Socialist Party. However, the deal fell apart, leading to a crisis between the two allies, which developed into a civil war in 1994.
The socialists in south were then crushed by the army of current President Ali Abdullah Saleh. Nowadays, some voices rise in the south, calling for disengagement from the north and the restoration of the southern state.