Southern African leaders launched a peacekeeping brigade on Friday as part of a planned African standby force to be deployed on peace missions and to tackle disarmament and humanitarian crises on the continent.

Zambian President Levy Mwanawasa officially launched the brigade, inspecting troops in front of regional heads of state at a summit of the 14-member Southern African Development Community (SADC) in Lusaka.

Cannons were fired and fighter jets screamed overhead.

"The SADC brigade shall ... serve in peace-building efforts including post conflict disarmament and demobilisation and humanitarian assistance to alleviate the suffering of civilian populations in conflict areas and support efforts on major natural disasters," Mwanawasa, the new SADC chairman, said.

The peacekeeping brigade, part of an Africa-wide effort to form an operational standby force by 2010, is expected to deploy in areas for a "limited duration", with a mandate from the United Nations, African Union or SADC.

Brigadier-General Malakia Nakanduungileh, the outgoing chief of staff of the brigade's planning department, described the new force as a victory for the region: "We are ahead of other regions, we are ready now."

The brigade is made up of contributions from SADC countries, with each force based in its country of origin, but the brigadier-general said that should not slow down rapid deployment missions.

It was not immediately clear when or where the brigade might be deployed first.

A brigade is typically composed of 5,000 troops. Nakanduungileh, a Namibian, told reporters it was not clear how big the force would be, saying it would depend on each mission's mandate.

Southern African heads of state are meeting in Lusaka this week to consider ways to address a political and economic crisis in neighbouring Zimbabwe, one of the biggest trouble spots in Africa and other issues.

Asked if the SADC brigade would be willing to help resolve the humanitarian crisis in Zimbabwe, Nakanduungileh said: "If the politicians decide so why not?"