ISIS: Facts you should know

Islamic State of Iraq and Syria on Tuesday released a video purportedly showing the beheading of a second American journalist, Steven Sotloff, and warning President Barack Obama that as long as US airstrikes against the militant group continue, "our knife will continue to strike the necks of your people."

This video comes days after the killing of US journalist James Foley.

What is ISIS?

• The terrorist group, Islamic State of Iraq and Syria (ISIS) was born out of the Sunni terrorist organization al-Qaeda.

• It is an banned Jihadi militant group in Iraq and Syria influenced by the Wahabi movement.

• ISIS was established in the early years of the Iraq war and pledged allegiance to Al-Qaeda in 2004.

• However, Al-Qaeda cut all ties with ISIS in February 2014, after a power struggle.

• Though the group has been active for many years, the seizure of Iraq's key cities of Mosul and Tikrit put it on the world's radar.

• It was known as ‘Islamic State in Iraq' in 2006, now as ‘Islamic State in Iraq and Syria' and also alternately known as ‘Islamic State in Iraq and the Levant'(Levant is a region which includes Syria, Lebanon, Israel, Palestine, Jordan, Cyprus and Hatay)

• The total number of Sunnis fighting for ISIS is unknown, but it is estimated to be in the tens of thousands.

• ISIS controls hundreds of square miles where state authority has evaporated. It ignores international borders and has a presence all the way from Syria's Mediterranean coast to south of Baghdad.

What are its aims?

• The aim of ISIS is to create an Islamic State across Sunni areas of Iraq and in Syria.

• ISIS wants to execute Shias and release Sunnis.

• ISIS has begun imposing Sharia law in the towns it controls. Sharia law covers both religious and non-religious aspects of life.

Who is the leader?

• Abu Bakr al-Baghdadi became the leader of the outfit in 2010.

• Baghdadi was graduated to the top job in 2010 after Abu Omar al Baghdadi was killed in a joint US-Iraqi operation.

Fallout out with Al Qaeda

• ISIS was separated from al Qaeda in 2013 when Osama bin Laden's replacement, Ayman al-Zawahiri, fell out publicly with al-Baghdadi.

• Qaeda's central command said in an online statement that ISIS failed to follow orders and so all connections with ISIS were severed.

• Al Qaeda said that ISIS is "not an affiliate with the al Qaeda group and has no organizational relation with it."