By Ulf Laessing
KHARTOUM (Reuters) - Sudan has released four foreigners who were detained three weeks ago near the border with South Sudan following weeks of heavy clashes between the two African neighbors, officials said on Sunday.
Sudan accused the four - a Briton, a Norwegian, a South African and a South Sudanese - of entering an oil-producing border area illegally to spy for South Sudan.
South Sudanese officials had denied Sudan's allegations, saying the men were working with the United Nations and aid groups clearing mines, and had got lost in the remote territory.
The four seemed to be in good health when they appeared on Sunday in civilian clothes at a brief ceremony in a defense ministry reception hall in the capital Khartoum.
They looked relieved but none of them spoke about the allegations nor touched soft drinks and water laid out on tables in front of them.
Norwegian John Sorbo only said in a brief statement authorities had treated them "very well" during their detention in military facilities in the Sudanese capital Khartoum.
"I'd just like to use the opportunity to thank (Sudanese officials) for the way they looked after us," he said.
Speaking alongside them, Sudan's Defence Minister Abdel Raheem Hussein said Khartoum had decided to release the four on request from former South African President Thabo Mbeki, who has been mediating their release.
"We launched an investigation and had great doubts about their intentions because they were arrested in a war zone," Hussein told reporters. "They were working for one of the two sides," he said without naming South Sudan directly.
"The President of the Republic decided to release them as a gesture of goodwill," he added.
Their release came after a meeting late on Saturday between Sudan's President Omar Hassan al-Bashir and Mbeki, who is trying to bring the two countries back to the negotiating table at the African Union in Addis Ababa.
"We asked President Bashir to release you," Mbeki told the four at the ceremony. "All of us will go together," he said.
Mbeki then left the defense ministry together with the four men who were driven away in a white van as part of his motorcade. Mbeki is due to fly to Juba on Sunday for talks with southern officials.
The arrest in April came after weeks of fighting along the 1,800 km (1,100 mile) contested border that brought the two countries closer to an all-out war than at any time since South Sudan seceded.
The southern nation, which became independent in July under a 2005 peace deal that ended decades of civil war, had seized the disputed Heglig oil area earlier in April, but then withdrew under heavy international pressure.
The neighbors are still at loggerheads over a raft of contentious issues including the exact position of the border, the status of citizens in one another's territory and how much the landlocked South should pay to export its oil through Sudan.
(Reporting by Ulf Laessing; Writing by Alexander Dziadosz and Ulf Laessing Editing by Maria Golovnina)