Violence has continued in south Yemen despite an offer of talks by Sanaa, which faces international pressure to quell domestic unrest and focus on a bigger global threat: al Qaeda.
Yemen, which has targeted separatists in security sweeps following an increase in southern unrest in recent weeks, offered last week to hear separatists' grievances. While protests diminished in recent days, some violence has continued, Reuters reported.
State media described the man who was killed, Wadie Juneidy, as a wanted and dangerous leader of a criminal gang who had been driving a stolen car. It said he was killed Saturday in an exchange of gunfire in the southern province of Abyan.
A southern opposition news website identified Juneidy as a separatist, however, and described his killing as an assassination. It said Juneidy was shot dead after security forces stopped him at a checkpoint, and he resisted arrest.
"They tried to arrest him without any legal basis, except that he resisted and refused to surrender himself," the Aden Press news website said, adding he was killed in "cold blood."
Separately, a court in southeastern Hadarmout province began the trial of 11 suspected separatists Sunday on charges including "threatening Yemen's unity," state media reported.
Yemen came to the forefront of Western security concerns after the Yemen-based regional arm of al Qaeda claimed responsibility for a failed attempt to bomb a U.S.-bound plane in December.
Al Qaeda in The Arabian Peninsula said in a statement posted on Islamist websites that a Saudi militant -- who it said had been active in raising funds in Saudi Arabia for fighters in Yemen, Iraq and Afghanistan -- was killed in a clash with government forces in southern Yemen.
Western allies and neighboring oil exporter Saudi Arabia fear al Qaeda is exploiting instability on multiple fronts in impoverished Yemen to recruit and train militants for attacks in the region and beyond.