"Some organisations helped us to de-mine the road. It is still rough, but traffic can now move from Koboko at the border with Uganda to Juba through Yei," George Riak, an SPLM/A official in Kampala, said on Tuesday.

He said the road became insecure in 1985 when the war in southern Sudan extended to the west and east of the River Nile. Those who insisted on using the route had to use military-escorted convoys to make it to Juba.

"The road is open because people are travelling on it, but it is not necessarily safe," Thomas Thompson, Sudan logistics officer for the UN World Food Programme (WFP), said on Wednesday.

"It is supposed to be open to military traffic only," he added.

On Tuesday, a group of some 70 members of the Lord’s Resistance Army (LRA) hijacked and looted a vehicle of the Swiss Foundation for Mine Action and five other local trucks and cars on the newly opened road between Yei and Juba, a humanitarian worker in the region, who did not want to be named, said. No injuries were reported.

The LRA, which has waged a war against the Ugandan government for 19 years, operates from bases in northern Uganda and southern Sudan. It is widely thought that the LRA's leader, Joseph Kony, ventures into Uganda to launch attacks on civilian targets then retreats to his southern Sudanese base.

Frequent LRA attacks on southern Sudanese targets have, since January, forced at least 9,000 southern Sudanese to flee across the border to northwestern Uganda, according to UN Refugee Agency, UNHCR.

Thompson added that the road had not entirely been de-mined to humanitarian standards, but expected that, in a few weeks, an eight-meter wide corridor would be ready and declared safe for travel.

At the height of the fighting, it took an escorted convoy over a month to make the 260-km journey that under normal circumstances would take four hours.

Businessmen, who had been flying their supplies from Khartoum to Juba for years, have now started using the road to transport their goods to the garrison town. Riak said that the road passes through the towns of Yei and Loka. In addition to easing transport to Juba, the newly opened route should boost trade between Uganda and Sudan.

In January 2005, the SPLM/A and the Sudanese government signed a comprehensive peace accord that ended over two decades of war. The fighting has killed at least two million people, uprooted four million more and forced some 600,000 to flee to neighbouring countries.

The SPLM/A suffered a setback in July when John Garang, its long-serving leader who under the agreement had assumed the post of Sudan's first vice-president, died in a helicopter crash on his way to southern Sudan from a meeting with Uganda's president, Yoweri Museveni.

In Khartoum, Garang was replaced by his deputy in the SPLM/A, Salva Kiir, and as the leader of the semiautonomous region of southern Sudan.