Done a bit of digging myself. To try and ensure an unbiased view I consulted an Islamic source - WikiIslam

"Sunni extremists accounted for the greatest number of terrorist attacks and fatalities for the third consecutive year," the report says. "More than 5,700 incidents were attributed to Sunni extremists, accounting for nearly 56 percent of all attacks and about 70 percent of all fatalities."

The report says that in 2011, a total of 10,283 terrorism attacks across the world killed 12,533 people. Terrorism also is blamed for 25,903 injuries and 5,554 kidnappings.

According to NCTC, of the 12,533 terrorism-related deaths worldwide, 8,886 were perpetrated by "Sunni extremists," 1,926 by "secular/political/anarchist" groups, 1,519 by "unknown" factions, 170 by a category described as "other", and 77 by "Neo-Nazi/Fascist/White Supremacist" groups.

The information comes from the 2011 NCTC Report on Terrorism, which is based on information available as of March 12, 2012.

Now, I have done half the work. Can someone let us know how many people were killed by US/UK attacks in the same period? I would be very surprised if it was vastly different.

Cheers

DtG