Yemeni troops opened fire on a protest against the army's deadly shelling of a funeral tent erected by the Southern Movement, killing two people on Saturday, an activist said.
Four demonstrators were also wounded when the troops opened fire outside the provincial governor's office in the southern town of Daleh, activist Majed Shuaibi told Agence France Presse.
Hundreds of residents joined the protest against Friday's shelling of the funeral tent, which killed 19 people, four of them children, medical sources said.
The Southern Movement -- which is campaigning for autonomy or outright secession of the formerly independent south -- had set up the tent for mourners paying their condolences after a man was killed in clashes with security forces in Daleh on Monday.
Those clashes erupted when secessionists tried to storm the governor's office to hoist the flag of the former South Yemen. The fighting left two policemen and a civilian dead.
In a statement, the supreme council of the Southern Movement headed by prominent activist Hassan Baoum, said: "The horrific massacre that the Yemeni occupation regime has committed... affirms the need for the people of the south to take up arms in face of the genocide it is committing" against them.
After British colonial rule ended in 1967, southern Yemen was independent until union with the north in 1990.
A secession attempt four years later sparked a brief but bloody civil war that ended with northern forces taking over the south.
Southern grievances have hindered the political transition following the 33-year rule of Ali Abdullah Saleh, who stepped down last year following Arab Spring-inspired protests.