At least two people have been killed in clashes between demonstrators and security forces in the city of Mukalla in southern Yemen, sources have told Al Jazeera.

Security measures have been tightened in Yemen on Saturday after thousands of people demonstrated in Hadramout, Aden and other areas south of the country.

Several cities in south Yemen were virtually paralysed as an armed clash between southern fighters and security forces wounded six people, witnesses and police said.

Schools and public offices were closed and shops shuttered on the second day of a protest movement over the killing of a tribal chief in a confrontation with the army.

A week of protests has been launched over the death of local tribal chief Said Ben Habriche, who was to be buried on Saturday.

He was among six tribesmen killed on December 2 in fighting which erupted when his bodyguards refused to hand over their weapons to soldiers at a checkpoint. Two soldiers also died.

His funeral was due to take place Saturday in Mukalla where the Southern Movement said its supporters had taken over the city's police station "without clashes".

Rapid intervention force

Four Southern Movement fighters and two policemen were wounded in an armed clash in Ataq, capital of Shabwa province, police said.

Security sources said armed men seized a rapid intervention force vehicle and police had to repel gunmen who briefly took over a telecommunications centre.

On Friday, a child and a rebel fighter were killed in the main southern city of Aden and in Mukalla, in southeast Yemen, medics and witnesses said.

Protest organisers are pressing authorities to hand over the suspect who killed Ben Habriche, and to provide jobs for southerners in the police force, army and oil sector.

Source: Al Jazeera and agencies