A White House official said the incident was an attempted act of terrorism. The FBI is investigating and President Obama, celebrating Christmas in Hawaii, was told of the incident about three hours after the plane landed, officials said. Obama has told White House officials that all appropriate measures be taken to increase security for air travel, a spokesman said. Nevertheless, officials said, they are not prepared to raise the terrorism alert level, currently at orange -- or the second-highest of five levels -- for domestic and international air travel.