With reports of up to 2,000 more Zimbabwean troops being sent to eastern Congo, the United Nations Security Council has called on all parties to avoid worsening the conflict.

The Security Council called for "an immediate end to military offensives and hostilities ... and respect for the sovereignty and territorial integrity of the Democratic Republic of the Congo".

Meanwhile President Nelson Mandela has continued his efforts to seek a peaceful solution to the crisis by meeting the Rwandan Vice-President Paul Kagame - allegedly a key supporter of the rebels.

The South African Foreign Minister, Alfred Nzo, said everyone had to realise that the problem in the Congo could never be resolved by military means.

Attack in south

Mr Kabila refuses to talk to rebels

The Zimbabwean, Angolan and Namibian presidents met on Wednesday and announced their decision to step up their military support for the Congolese government.

President Robert Mugabe said his troops would take part in a new offensive against the rebels in their east, the source of their power.

The rebels say they are not deterred.

After capturing the strategically important town of Kindu, 1,200 km east of Kinshasa last week, they now say they have attacked the southern diamond mining town of Mbuji-Mayi and penetrated parts of the town. However residents report no fighting. Mandela peace drive 'upstaged'

BBC's Jane Standley: "The Congolese conflict is steadily drawing in more African countries"

The BBC Africa Correspondent, Jane Standley, says the Congolese conflict is steadily drawing in more African countries - with up to 10 believed to be involved.

The extension of the war to the east, she says, sharply upstages renewed attempts by South African President Nelson Mandela to mediate a peaceful solution.

Mr Mandela is engaged in a series of meetings with key players in the war. Aides say he will meet Namibian President Sam Nujoma and Congolese rebels next week.

Rebels 'killed Zimbabwe troops'

President Mugabe already faces domestic discontent about the escalating cost of the war and the death and capture of his soldiers.

On Monday, rebels captured 16 Zimbabwean soldiers in the eastern town Kabalo.

Zimbabwean government sources said the captured troops were part of a reconnaissance team to the east.

The rebels have offered to negotiate their release.

Meanwhile, according to reports, one of President Kabila's top army commanders has defected to the rebels' side.

Rebels took the strategic town of Kindu last week

Colonel Songolo Nura commanded forces in the southern province of Katanga.

In an interview on Rwandan radio, he said: "I joined...because I saw Kabila as a corrupt leader who heads a tribalistic organisation."

There are also reports that the country's finance minister, Fernand Tala-Ngai, has been arrested.