S. Sudan says Khartoum barge ban 'disaster'

South Sudan said Wednesday Khartoum's decision to stop the return of hundreds of thousands of Southerners by barge on the White Nile was a looming disaster, and that alternative means were untenable.

Sudan early this week halted the use of barges by South Sudanese returning home on suspicion the vessels were being used to reinforce troops near the two former civil war foes' tense border.

"This situation can be summed up in five words: a disaster waiting to happen," said Atem Yaak Atem, Juba's deputy information minister.

Up to 700,000 ethnic Southerners are estimated to still be in Sudan ahead of an April 8 deadline for them to either go South, or normalise their status with the Khartoum authorities.

Over 364,000 South Sudanese have already returned to their homeland since October 2010 from the north, where they fled to during decades of civil war.

However, the United Nations is preparing for a "potential large influx" of refugees as the deadline to return looms.

South Sudan Humanitarian Affairs Minister Joseph Lual Achuil told reporters that Sudan will only allow those returning to use trains, trucks or planes.

"We have four trains we were supposed to move since December, and they have not moved until now," said Achuil, describing rail transport as a "nightmare."

The route by road goes through Bentiu, the capital of South Sudan's oil-producing Unity state -- a heavily mined area with a proliferation of militia groups that Juba accuses Khartoum of funding.

"You know how insecure that route is, and that is the route we have been given," Achuil said.

"I don't know where my ministry or whoever is concerned will get the money to transport 700,000 people by air."

Since the South seceded last July, the two countries remain at odds over border demarcation, oil wealth and accuse each over of supporting rebels in the other's territory, sparking fears of renewed fighting.