From the water-is-wet department, via the Guardian:
Religious extremism has become the main driver of terrorism in recent years, according to this year’s Global Terrorism Index. The report recorded 18,000 deaths in 2013, a rise of 60% on the previous year. The majority (66%) of these were attributable to just four groups: Islamic State (Isis) in Iraq and Syria, Boko Haram in Nigeria, the Taliban in Afghanistan, and al-Qaida.

Overall there has been a fivefold increase in deaths from terrorism since the 9/11 suicide attacks. The report’s authors attribute the majority of incidents over the past few years to groups with a religious agenda. …
More than 80% of deaths from terrorism in 2013 occurred in just five countries: Iraq, Afghanistan, Pakistan, Nigeria and Syria. …
The number of incidents from nationalist separatist groups has remained relatively stable in the years since while religious extremism has grown.
It’s a sober reminder that most acts of terrorism are perpetrated by Muslims against other Muslims.