Alleged Takfir connections have popped up elsewhere over the past year, including France and Jordan. In Belgium, security forces are looking into possible links between the Nov. 2 slaying of van Gogh and recent anonymous threats against politicians.
The uncompromising Takfir doctrine has been around for decades -- denouncing even moderate Muslims as "infidels." But global communications and louder militant voices could be offering fresh energy. It's part of larger worries about rising Islamic extremism in an Internet age when texts and sermons reach nearly everywhere and peripheral movements can quickly gather momentum.
"Authorities are looking in the wrong direction," said Azzaz Tamimi, head of the Institute of Islamic Political Thought in London. "Many Muslims feel under pressure. This pressure and anger can make people radicalized. Extremism is not just with big terrorist groups. It's out on the streets, and radical movements are easily tapping into it."
"Takfir," literally "excommunication," refers to scorning societies perceived as corrupt and deserving retribution. "Hijra" refers to withdrawing from anything considered against Islam.
The name was coined by Egypt's government-controlled press in the 1970s in an attempt to make it scary and alien to mainstream Muslims. Takfir is often described as part of the founding forces for today's major terrorist networks. But it's not easy to draw clear connections.
Islam researchers and scholars say terror groups might draw general encouragement from Takfir's militant dogma. But Takfir's core followers -- an unknown number that could be in the thousands, experts say -- are too renegade and insular to offer practical support to networks such as al-Qaida.
Takfir denunciations, in fact, often cover anyone who is not a committed follower, including al-Qaida leader Osama bin Laden -- although his chief lieutenant, the Egyptian-born Ayman al-Zawahri, is reportedly a Takfir follower and has lectured on its tenets.
In 1995, an alleged Takfir gunman attacked bin Laden's compound in Sudan. Five years later, a suspected Takfir attacker killed 20 worshipers in a mosque as part of feuds with rival Muslim sects in the country.
