Daesh officially declared war on Saudi Arabia on Thursday, shortly after the wealthy Middle Eastern nation announced that it had formed a 34-state Islamic military alliance against the group.Daesh militants made their warning via an execution video; showing a cruel execution of a man who they present as a 'Saudi collaborator', reported UK daily Mirror.In the video Daesh accuses the Arabic Kingdom of cooperating with the counter-terror coalition which the militants refer to as 'crusaders'.The video shows galloping horses, warplanes and gun fights in a desert. Later, a man in a blue boilersuit branded as a 'collaborator' is executed.Daesh terrorists challenge Saudi Arabian troops to face them in Syria, while stating that the Riyadh leadership is now a 'target'.A long list of Arab countries such as Egypt, Qatar, the United Arab Emirates, together with Muslim-majority countries such as Turkey, Malaysia, Pakistan and several African states were mentioned in the 34-state alliance."The countries here mentioned have decided on the formation of a military alliance led by Saudi Arabia to fight terrorism, with a joint operations center based in Riyadh to coordinate and support military operations," said a statement released by Saudi Arabia.Meanwhile, the UN Security Council unanimously adopted a plan Thursday aimed at disrupting revenue that the Daesh extremist group gets from oil and antiquities sales, ransom payments and other criminal activities.The proposed resolution urges countries to share information about extremist groups and calls for a report within 120 days on what every country is doing to tackle the financing of Daesh and al-Qaida; stressing that supporters of the groups will be subject to U.N. sanctions, including an asset freeze, travel ban and arms embargo.