Ayman al Zawahri vowed to avenge the death of al Qaeda leader Abu Laith al Libi, who was killed in an airstrike in North Waziristan in January. “No chief of ours had died of a natural death, nor has our blood been spilled without a response,” Zawahri said in a video released on a jihadi website. An al Qaeda -linked website has threatened to killed Dutch MP Geert Wilders for a short film criticizing Islam.