(VOVworld) - Al Qaeda leader Ayman al-Zawahiri has called on young Muslim men in the US and the Western countries to carry out lone-wolf attacks and urged greater unity between militants.

Ayman al-Zawahiri calls for fighters to co-operate with the IS. (Photo: Reuters)

In an audio recording posted online last Sunday, Zawahiri incited Muslims to conduct attacks on the nations which make up the US-led coalition in Iraq and Syria.

He called for moving the war to the heart of the homes and cities of the West and specifically America.

In the audio message, Zawahiri refused to endorse the IS’s self-proclaimed caliphate but affirmed that his organization is ready to cooperate with the IS to fight Western countries.

Zawahari also insisted on unity among Muslim militants in Syria and Iraq and the formation of an independent sharia court to settle disputes.

It was not clear when the recording was made but references to former Taliban leader Mullah Mohamed Omar as being alive suggest it is at least two months old. Omar's death was announced by Afghanistan's government in late July.