South Sudan's information minister, Michael Makuei Lueth told reporters in the capital, Juba on Saturday that as many as 25,000 youths were marching on the city of Bor. He said the figure was based upon intelligence the government had received from within the tribal militia itself.

"He has decided to mobilize the youth in the name of his tribe," Lueth said, referring to former Vice President Riek Machar, a member of the Nuer ethnic group. Machar, who was sacked as vice president last summer, is accused by President Salva Kiir, of the Dinka ethnic group, of sparking the fighting by attempting to topple him in a coup earlier this month. Machar has denied this.

Most of the residents of Bor are Dinka and Lueth said the South Sudan army, which recaptured the town this past week after it had briefly been held by the rebels, would do all it could to protect the civilian population. At the same time though, it said it remained to be seen what the outcome of the apparent impending battle would be.

"It's hard to predict what will happen," he said. "This is war."

The youths said to be marching on Bor are known as the White Army due to the white ash its fighters smear on their skin in order to protect themselves from insects.

Despite the reported rebel march toward Bor, Army spokesman Colonel Philip Aguer told the AFP news agency that the situation there remained calm in Bor on Saturday. Speaking to the Associated Press, though, Aguer said the army had repelled attacks by Machar's forces. Aguer said the army "is fighting back, but it is the other side that is attacking us."

Ceasefire offer rejected

In view of this and the anticipated battle for Bor there seems to be virtually no prospect for a quick resolution of the conflict, which many fear could be sliding into a full-blown civil war.

Friday's offer by President Kiir to end hostilities with the rebels, which came after a regional crisis meeting in Nairobi, was rejected by Machar, who was not represented at the talks. Machar said that he was open to entering negotiations towards a ceasefire, but that this could only be reached if such talks involved representatives of both parties to the conflict.

Since the fighting broke out on December 15, more than 1,000 people are believed to have been killed and 120,000 others force to flee.

pfd/lw (AFP, AP, dpa)