Afghanistan has launched the main phase of a national campaign to disarm tens-of-thousands of irregular troops loyal to powerful regional commanders, widely known as warlords. The program is seen as crucial to the country's stability before national elections in September.

The disarmament campaign kicked off in Kabul, where fighters of what is known as the 99th Rocket Brigade turned in 69 of their Soviet-era surface-to-air missiles.

Speaking on the occasion, Afghan Deputy Defense Minister Abdur Rahim Wardak urged all troops who are not part of the new U.S.-trained Afghan National Army to surrender their weapons, warning that the central government would deal with anyone opposing disarmament.

Moneol de Almeida e Silva, the United Nations spokesman in Kabul, said private military units are contributing to instability. "The military units that are to be down-sized are not active in the protection of the country's security? Quite the contrary: many of them have been in the past two years involved in factional fighting which is a continuing cause of instability," he said.

The campaign is designed to take weapons out of the hands of scores of private armies owned by powerful regional warlords, as well as fighters associated with the Afghan defense ministry.

At least 40 percent of these forces are due for demobilization by the end of June, under the foreign-funded program.

The present campaign should have started a month ago, but regional warlords resisted the move. Afghan officials say they have now received assurances from these commanders that they will cooperate.

The pilot campaign began in October last year when more than 6,000 men were disarmed and given new civil jobs.

Observers say the presence of tens of thousands of armed fighters and an ongoing insurgency led by the ousted Taleban government could undermine free and fair elections in September. The U.N. spokesman Moneol de Almeida e Silva says disarmament will minimize voter intimidation.

"A national election could be a genuine exercise in free political choice only after guns cease to be a tool in the hands of local power holders," he said.

Afghan militia forces were part of the loose alliance that joined the United States-led coalition in overthrowing the Taleban two-years ago for harboring international terrorists. The private Afghan fighters were left in place to provide security across the country until a regular national army could be established.

Now, despite the existence of the U.S. trained Afghan National Army, many of these militias remain in place.