FACTBOX: Persons accused in 2009 of plots against U.S. targets

(Reuters) - The incident in which a passenger ignited a fire on a plane as it approached Detroit's airport is the latest case of an individual suspected or accused of plotting to attack targets in the United States. Here are some of the cases that were reported by authorities in 2009.

Najibullah Zazi, an Afghan-born man who is a permanent U.S. resident, was charged in September with plotting to set off bombs in New York City. He has pleaded not guilty. Prosecutors allege Zazi received al Qaeda training in Pakistan on bomb-making and had accumulated large quantities of bomb-making chemicals. Attorney General Eric Holder has said plot is one of the most serious security threats to the United States since the September 11, 2001, attacks.

Four Muslim men were arrested in May and charged with a plot to blow up two synagogues in New York City and shoot down planes at an Air National Guard base in New York state. Police say the four men -- Americans James Cromitie, David Williams, Onta Williams and Haitian national Laguerre Payen -- had no known links to al Qaeda. Police say the men had been watched by authorities for nearly a year and were caught in a sting operation. All four men have pleaded not guilty.

Tarek Mehanna of Massachusetts was charged in October with conspiracy to provide material support to terrorists. He has pleaded not guilty. Prosecutors say Mehanna, who is believed to be a U.S. citizen, and co-conspirators traveled to the Middle East seeking training, discussed attacking a shopping center, and distributed videos promoting holy war. According to the FBI, Mehanna and Ahmad Abousamra, who fled to Syria in 2006, had sought automatic weapons for an attack on an unidentified shopping mall.

Michael Finton, also known as Talib Islam, was charged in September with trying to blow up a federal building in Springfield, Illinois, the state capital. Finton has pleaded not guilty. Prosecutors say Finton was arrested in a sting operation as he used a cellphone to try to detonate a bomb he believed was inside a van he had parked outside of the building. They say Finton, who converted to Islam while in prison, had idolized an American who allied with the Taliban, John Walker Lindh.

Jordanian national Hosam Maher Husein Smadi was arrested in September and charged with attempting to bomb a skyscraper in Dallas. Authorities say Smadi, who was under FBI surveillance, was arrested after he placed an inactive car bomb near a 60-story office tower in downtown Dallas. He has pleaded not guilty. The FBI said it became aware of Smadi after he tried to contact an al Qaeda cell on the Internet.

(Compiled by Eric Beech)