The United States has ruled out the prospect of military co-operation with Iran, over the escalating crisis in Iraq.

Remarks by Secretary of State John Kerry, saying “I wouldn’t rule out anything that would be constructive," caused speculation over whether the two countries would work together.

This was soon followed by statements from the Pentagon ruling out any joint military possibilities.

The claimed execution of 1,700 prisoners by the Islamic State of Iraq and Levant (ISIS) in the Iraqi city of Tikrit almost certainly amounts to war crimes, stated the UN High Commissioner for Human Rights Navi Pillay.

Videos and photographs have emerged on various websites linked to ISIS, showing executions of dozens up of members of the Iraqi army. ISIS claims to have executed 1,700 after capturing the city of Tikrit. It comes as the group claim to have made further territorial gains, capturing the town of Tal Afar and its commanding general, whom they will publically execute, according to reports.

Pillay said in a statement earlier today,

“Based on corroborated reports from a number of sources, it appears that hundreds of non-combatant men were summarily executed over the past five days, including surrendered or captured soldiers, military conscripts, police and others associated with the Government,”

The High Commissioner went on to add,

“Although the numbers cannot be verified yet, this apparently systematic series of cold-blooded executions, mostly conducted in various locations in the Tikrit area, almost certainly amounts to war crimes”.

“It is in our interests for this Jihadist extremist group to be stopped in its tracks. I understand entirely why people say ‘it is nothing to do with us and I don’t want to hear about it’”

UN High Commissioner Navi Pillay has warned of war crimes occurring in Iraq, as militant group Islamic State of Iraq and the Levant (ISIS) released images of the shooting of dozens of captured Iraqi soldiers.

The images, released on a militant website appear to show the killings, reportedly taking place north of Baghdad, with the Iraqi Army’s Lieutenant General Qassim al-Moussawi confirming their authenticity.

A Ukraininan military plane was shot down by Pro-Russian separatists, killing all 49 crew and troops aboard.

Ukraine's president Petro Poroshenko has vowed to retaliate, saying that "all those involved in cynical acts of terrorism of this magnitude must be punished."

Despite denials from Moscow, the United States believes that the separatists are being armed by Russia. State Department spokesperson Marie Harf said in a statement on Friday:

The United States has announced it is sending an aircraft carrier into the Gulf, to increase its options to deal with the conflict in Iraq.

The USS George HW Bush, capable of carrying dozens of fighter jets, was ordered into the Gulf by Defence Secretary Chuck Hagel, alongside a guided-missile cruiser and a destroyer.

With ISIS advancing closer to the Iraqi capital, Iran has said it did not rule out working with the US in fighting the militants.

Tens of thousands of Cambodian migrants have left Thailand, where there are fears that the military government may crack down on illegal workers, with reports of forced deportations emerging.

“President Obama met with his senior foreign policy team yesterday afternoon. We had a comprehensive meeting regarding the events in Iraq. We discussed a range of options including military action.”