International aid agencies are mounting an emergency relief operation to help tens of thousands of people who have fled large-scale fighting between Sudan's army and former southern rebels in and around the oil-rich town of Abyei. Lisa Schlein reports for VOA from Geneva.

Heavy fighting erupted Tuesday between the northern Sudan Armed Forces and southern Sudan People's Liberation Army. More than 20 northern soldiers have reportedly been killed and an unknown number of southerners.

Aid agencies estimate around 60,000 people have fled their homes in Abyei and found refuge in Agok and in 18 surrounding villages. The International Organization for Migration says it believes another 10,000 people have moved south towards the town of Turalei and beyond.

IOM spokesman Jean-Philippe Chauzy says two convoys of relief goods have left the towns of Wau and Juba. He says they are expected to arrive in the town of Agok, located some 25 kilometers south of Abyei, over the weekend. He says the relief items will be distributed to 60,000 displaced people.

"The situation of the displaced is said to be very bad and in desperate need of shelter, food, water and medical assistance," he said. "Of course the relief operation is incredibly complicated because of chronic insecurity, because of the poor state of roads. There again we have pre-positioned some assistance in some of the warehouses we have in the region, most notably in Juba and in Wau. We will basically make this assistance available to this particular emergency in and around the town of Abyei."

Other aid agencies are participating in this emergency operation. The UN Children's Fund has loaded primary healthcare kits, nutritional supplies and fuel onto the IOM trucks. The World Food Program has already distributed food to 37,600 displaced people and plans other distributions.

The World Health Organization has pre-positioned emergency supplies in the area in preparation for a possible outbreak of cholera. The UN Population Fund has sent reproductive health items to the region.

North-south tensions have been rising for months in Sudan, with the south accusing the government in Khartoum of delaying implementation of the peace deal.

Both the north and south covet the oil-rich town of Abyei. Three years after the Comprehensive Peace Agreement was signed ending Sudan's long-running civil war, the area remains disputed. Abyei is still not governed by a joint administration as stipulated by a special agreement.

Analysts warn Abyei could be the flashpoint to re-ignite war in Sudan if this issue is not resolved quickly.

In addition to Abyei, the sides are divided over power and wealth-sharing issues and the continued presence of Khartoum government troops in the south.

Southern Sudan gained partial autonomy under the 2005 Comprehensive Peace Agreement. The accord gives southern Sudan the right to vote on secession in 2011.