NNA - Thousands of men who worked as intelligence operatives under former president Omar al-Bashir and have ties to his Islamist movement are fighting alongside the army in Sudan's war, three military sources and one intelligence source said, complicating efforts to end the bloodshed.

The army and a paramilitary force have been battling each other in Khartoum, Darfur and elsewhere for 10 weeks in Africa's third largest country by area, displacing 2.5 million people, causing a humanitarian crisis and threatening to destabilise the region. Reinforcements for either side could deepen the conflict.

The army has long denied accusations by its rivals in the Rapid Support Forces (RSF) that it depends on discredited loyalists of Bashir, an Islamist long shunned by the West, who was toppled during a popular uprising in 2019.

In response to a question from Reuters for this article, an army official said: "The Sudanese army has no relation with any political party or ideologue. It is a professional institution."

Yet the three military sources and an intelligence source said thousands of Islamists were battling alongside the army.

"Around 6,000 members of the intelligence agency joined the army several weeks before the conflict," said a military official familiar with the army's operations, speaking on condition on anonymity.

"They are fighting to save the country."

Former officials of the country's now-disbanded National Intelligence and Security Service (NISS), a powerful institution composed mainly of Islamists, confirmed these numbers.

An Islamist resurgence in Sudan could complicate how regional powers deal with the army, hamper any move towards civilian rule and ultimately set the country, which once hosted al Qaeda founder Osama bin Laden, on a path for more internal conflict and international isolation.

Reuters spoke to 10 sources for this article, including military and intelligence sources and several Islamists.

In a development indicative of Islamist involvement, an Islamist fighter named Mohammed al-Fadl was killed this month in clashes between RSF forces and the army, said family members and Islamists. He had been fighting alongside the army, they said.

Ali Karti, secretary general of Sudan's main Islamic organisation, sent a statement of condolences for al-Fadl. --- Reuters