FACTBOX: Recent suspected terrorism plots on U.S. soil

(Reuters) - Four people have been charged in connection with a plot against New York's John F. Kennedy International Airport, U.S. officials said on Saturday.

The following are some recent cases of suspected terrorist plots in the United States.

* On May 8, six suspected Islamic radicals were detained on charges of plotting to attack the U.S. army base at Fort Dix in New Jersey with rocket-propelled grenades and automatic weapons.

The group, which was not believed to have links to any foreign organizations, had amassed semi-automatic assault rifles, shotguns and handguns while trying to get the more sophisticated weaponry, federal authorities said.

* On July 7, 2006, U.S. officials said they had thwarted a foreign-based plot to stage a suicide bombing of a rail tunnel in New York later in the year and three suspects were being held abroad, one of them in Lebanon.

U.S. authorities worked with intelligence agencies in six countries to crack the planned attack on the PATH rail system linking Manhattan and New Jersey under the Hudson River, an FBI official said.

* On June 23, 2006, seven men were charged with conspiring to blow up the landmark Sears Tower in Chicago and the FBI building in Miami in a mission they hoped would be "just as good or greater" than September 11, U.S. officials said.

The FBI said the discussions to attack the 110-story Sears Tower -- the tallest building in the United States -- were "aspirational rather than operational."

The men were accused of pledging loyalty to Osama bin Laden's al Qaeda to seek support from it for their desire to "wage war" against the U.S. government and build an Islamic army.