A protester was killed and several people were shot and wounded, including three police, as a separatist march in the southern city of Aden turned into a gunbattle on Saturday, police and opposition sources said.
The demonstration was staged in the Mansura quarter of the port city to commemorate the day in 1994 when northern troops seized the south after a brief rebellion.
"The police opened fire on the march, killing a demonstrator and wounding three others," said Southern Movement activist Nizar Saidi.
A hospital source confirmed the death and said seven other demonstrators were wounded in an exchange of gunfire. Police said armed protesters fired first and that three policemen were wounded.
The southern movement, which complains that the region has been marginalised by the central government, is demanding autonomy, or even independence. Southern Yemen was a separate nation before 1990.