The Tamil Tigers of Sri Lanka are undoubtedly one of the most organized, effective and brutal terrorist groups in the world. They invented the suicide vest and, according to the FBI, are the only terrorist group to have assassinated two world leaders. The rebels, based in northern and eastern Sri Lanka, have been waging a violent offensive against the central government on and off for more than 20 years. Federal forces recently announced they had captured the Tigers' capital, Kilinochchi, but it's a safe bet that, regardless of territory lost or possibly dwindling ranks, the guerillas will not give up their fight willingly.
The Tamil Tigers, which include 5,000 to 10,000 guerillas, are fighting to secede from the the island country of Sri Lanka. They originally immigrated to Sri Lanka from southern India and make up 10 to 15% of the population, compared to the majority Sinhalese, who constitute about 75%. In 1972, the Sinhalese-controlled Sri Lankan government declared Sinhala and Buddhism the official language and religion. The Tamils, who practice Hinduism and have their own language, took this action as an affront, and Vellupillai Prabhakaran founded the Tigers soon after. The group is formally known as the Liberation Tigers of Tamil Eelam (LTTE).