NEW YORK (AP) - The State Department is renewing its global terrorism alert for U.S. citizens following the attack by al-Qaida linked extremists on an upscale shopping mall in Nairobi, Kenya. In a new "worldwide caution" issued Wednesday, the department said it continued to be concerned about threats to U.S. citizens and interests in Europe, Asia, Africa and the Middle East. It said attackers could use a variety of tactics, including suicide operations, assassinations, kidnappings, hijackings and bombings. It said potential targets could be high-profile sporting events, residential areas, business offices, hotels, clubs, restaurants, places of worship, schools, public areas, shopping malls and other tourist destinations where Americans gather in large numbers. The new warning follows the Nairobi mall attack in which at least 67 people, including 18 foreigners, died.