Sudan on Thursday received 13 prisoners of war released by South Sudan, the Red Cross said, following their capture in recent fighting along the poorly demarcated border between the two countries, dpa reported. The 13, military personnel who were captured during fighting over the Heglig oil field, which has heightened tensions between the two sides. They were flown from the South Sudanese capital Juba to Cairo and on to Khartoum. "We're extremely pleased to have brought these men back to their home country," said Melker Mabeck, the head of the International Committee of the Red Cross (ICRC) team in Juba. South Sudan, which called the release of the prisoners a humanitarian gesture, alleges Sudan is holding some of its fighters and has asked for the Red Cross to be allowed access to them. South Sudan's speaker of parliament, James Wani Igga, on Wednesday called on youth of the fledgling country to mobilize and join the armed forces, saying they should "never surrender." Sudanese media reported that the parliament in Khartoum proposed a new bill, the "Repulsion of Aggression and Accountability of Aggressor Act, 2012," which would restrict negotiations with South Sudan. It would also place effective economic sanctions on Juba. South Sudan is dependent on imports from the Sudan and a trade cut-off would choke the country, declared independence from Sudan in July. In January, the South Sudan shut down oil production, as it must export through northern pipelines and the two sides cannot reach a deal on revenue sharing. The official Sudan News Agency announced, however, that progress was being made on negotiations between the United Nations and Khartoum on allowing aid workers access to troubled areas. The African Union this week called for the parties to resume full negotiations within two weeks and reach a deal within three months on all outstanding issues, including the question of borders. It noted that relations between the two countries that came into being after decades of civil war have never been worse.