For the past six months, protesters have been demanding President Saleh to step down  [Reuters]

Tens of thousands of opponents and supporters of President Ali Abdullah Saleh, convalescing in Saudi Arabia, have held rival rallies in the Yemeni capital, Sanaa.

Friday's anti-regime protests also took place in several provinces, including Yemen's second largest city of Taez, in Ibb, Shabwa, Saada and Marib, witnesses said.

A smaller number of Saleh's loyalists gathered in a southern district of Sanaa for a Friday of "loyalty" to the veteran leader, hospitalised in Riyadh from bomb wounds he sustained in an attack on his palace compound on June 3.

Yemen opposition forces have deployed armoured vehicles in the capital Sanaa and dispersed a group of people who wanted the demonstrators' tents removed.

A large number of troops and armoured vehicles guarded the 'Change Square' as anti-regime protesters took to the streets after noon prayers for what they called 'Friday of Patience'.

"We will remain steadfast and preserve the peacefulness of our revolution until this regime falls," a cleric said, appealing for calm and persistence.

Protesters have camped for months in the area, growing increasingly frustrated that their mass movement of six months has yet to shake loose the 69-year old president's grip on power.

Even after he was forced to go to Riyadh for medical treatment following a bomb attack on his palace in June, Saleh has vowed to return to oversee a national dialogue and elections but the opposition accuses him of stalling tactics.

In the south of the country, security forces clashed with fighters near one of several towns under the control of al-Qaeda-linked militants who have taken advantage of Yemen's political turmoil.

Six soldiers and five militants were killed when fighting broke out in the town of Zinjibar, a security official said.

The six-month confrontation between the regime and its opponents has claimed the lives of hundreds across the nation and pushed Yemen, already one of the world's poorest countries, to the edge.