Over 200 ISIS fighters have surrendered to the Afghan army in the country's north, with some reports suggesting they handed themselves over to the military rather than be captured by the Taliban.

Among the fighters who gave themselves up after days of intense fighting with the Taliban were the leader in the north of the Islamic State Khorasan -- or IS-K, as the terror group is known in Afghanistan -- Habib Rahman, and his deputy, according to a spokesman for the local Jawzjan provincial government, Mohammad Reza Ghafori.

IS-K has fought for the past few years against the more established and widespread Taliban insurgency as they vie for influence and the Afghan government struggles to assert control.

Taliban spokesman Zabiullah Mujahid said in a statement that 153 IS-K fighters had been killed, more than 100 injured and 134 captured. He added the surrender meant the Taliban had now cleared the north of Afghanistan of IS-K.

Yet it remained unclear exactly why the IS-K fighters had surrendered. A spokesman for the Afghan ministry of defense, Mohammad Radmanish, said the IS-K fighters surrendered because of an Afghan army onslaught instead. The US military has also expended significant resources, and lost several soldiers, in assisting Afghan forces fighting IS-K in the country's east.

Mufti Nehmatullah, the IS-K deputy leader in the north, said the fighters surrendered because "we were tired of fighting and pressure was on us from both sides." He added that the Taliban repeatedly asked the fighters to join them but "we chose to join Afghan security forces rather than the Taliban." (CNN)

•An Islamic State Khorasan member, second right, speaks to a journalist after he surrendered to government security forces.