Al-Qaeda-linked Al-Nusra Front has issued a new threatening audio message featuring its leader warning the West “will pay the heaviest price” for its actions. The Syrian group is reportedly now joining up with the estranged Islamic State militants.

The leader of Syria’s most prominent terrorist group, Abu Mohamad al-Golani, in denouncing the US-led air strike campaign, has urged Westerners everywhere to do the same “by standing against the decisions of your rulers,” otherwise bloodshed would be brought to their soil.