"Gunmen opened fire from assault rifles and killed Abdullah Abdul-Muttalib, a prominent security commander in Mudiyah village of southern Abyan province," the government source said on condition of anonymity.
The armed attack targeted the security officer while he was returning to his house located in Mudiyah, said the official.
Mudiyah, located in the eastern part of Abyan province, is witnessing an increase in armed attacks against security forces loyal to the Southern Transitional Council (STC).
Last month, heavy STC forces were deployed in several areas of Abyan in an attempt to confront any advance by the Saudi-backed Yemeni government forces from neighboring Shabwa province.
In August, the STC forces seized the strategic southern city of Aden and other neighboring main cities including Abyan, following deadly clashes with the government forces.