Sudan has denied that its troops threatened South African peacekeepers in Darfur to stop Sudanese president Omar al-Bashir's arrest in South Africa.

The United Nations has also denied a media report by South African website News24 on Tuesday that Sudanese troops had surrounded South African peacekeepers in the western region of Darfur until Bashir returned to Khartoum.

According to the Johannesburg-based site, about 1,400 South African soldiers in Darfur were surrounded by heavily armed Sudanese troops at the UN military bases in Kutum, Mellit, and Malha. The media report quoted the South African National Defence Union spokesman, Mr Pikkie Greeff, as confirming the incident.

However, the Sudanese army spokesman, Colonel Alswarmy Khalid Saad, denied the claims. He told the press in Khartoum on Tuesday that Sudan’s army had not taken any such action against the soldiers.

“There is no military conflict between the two nations to involve the army. We respect the presence of the South African troops according to our obligation as they are part of the UN forces in Darfur,” Col Alswary said.

The UN also released a statement Tuesday echoing the denial.

"South Africa currently has 802 members of an infantry battalion deployed in Kutum, Malha and Mellit team sites in North Darfur. We can confirm that the mission's South African troops were not held hostage or under any threat as reported in the media," UN spokesman Farhan Haq said in a statement.

Bashir, who was due to attend an African Union summit in Johannesburg, left South Africa on Monday in defiance of a Pretoria court that later said he should have been arrested to face charges at The Hague-based International Criminal Court.

South Africa's government let Bashir leave unhindered.

The ICC issued arrest warrants for Bashir in 2009 and 2010, accusing him of masterminding genocide and other atrocities in his campaign to crush a revolt in the Darfur region, a conflict that killed as many as 300,000 people, the United Nations has said.

A joint African Union-United Nations Mission (UNAMID) has been deployed in Darfur since 2007 with a mandate to stem violence against civilians.

Law and order have collapsed in much of Darfur, where mainly non-Arab rebels took up arms in 2003 against the Arab-led government in Khartoum, accusing it of discrimination.