The Sudanese government has banned and closed the offices of the Sudanese People's Liberation Movement-North (SPLM-N), a major opposition party, a senior SPLM-N member says. "You will not longer have any activities in Sudan a security officer told us," says Izdihar Juma, member of the SPLM-N's political office. Juma says that security officers came to the SPLM-N's main office in Khartoum and in other Sudanese states and took control. "They have taken over the offices, in all states, and we cannot enter," she says. "Some activists have been arrested," she added. The decision to ban the SPLM-N in Sudan comes in the aftermath of fighting between the Sudanese army and SPLM-N ex-rebels in Blue Nile state that erupted late last Thursday. Blue Nile is a border state with the newly independent South Sudan. As a result of the fighting, Sudanese President Omar al-Bashir declared a state of emergency in Blue Nile state and sacked its elected governor, Malik Agar, chair of the SPLM-N. Both parties accuse each other of starting the fighting. UNHCR says it has received reports of some 16,000 people fleeing across the border into Ethiopia. Fighting in Blue Nile state comes nearly three months after similar fighting broke out in South Kordofan state between the Sudanese army and SPLM-N former rebels there. SPLM-N represented the northern Sudanese division of the SPLM during the Sudanese civil war. SPLM now governs South Sudan. "They have been banned because they now are illegal; there is no 'north sector'," says Rabi Abd al-Ati, a senior member of the ruling National Congress Party (NCP). "It is not a matter of force, but a matter of constitutionality; there was an SPLM party but there is no political party registered as SPLM-N now according to the Political Parties Act," he says. Juma says that she and her party members intend to challenge the decision. "We are going to bring a case in court against this decision," she said.