Cleveland ? Three Muslim men from the Middle East have been charged with plotting terrorist attacks against U.S. and coalition troops in Iraq and other countries.

One of the men, a citizen of both the U.S. and Jordan, also was accused of threatening to kill or injure President Bush, according to an indictment released Tuesday.

All three had lived in Toledo within the past year and were arrested over the weekend – two of them in Toledo, the third in Jordan, authorities said.

An unidentified person with a military background helped the U.S. government foil the plot by working with the suspects while secretly gathering evidence, according to the indictment.

Atty. Gen. Alberto Gonzales also did not exclude the use of warrantless wiretapping in the investigation, but said prosecutors were careful not to jeopardize the case.

“This case stands as a reminder of the need for continued vigilance in the war on terrorism,” he said at a news conference in Washington.

The three pleaded not guilty in federal courts in Cleveland and Toledo. The most serious charges could bring life in prison.

Gonzales and other officials refused to say whether an attack was imminent. FBI agents monitored the defendants for about a year and a half, Assistant U.S. Attorney Craig Morford said at a news conference in Cleveland.

“What we can tell you is, from the indictment, it’s very clear that their activities and their intentions were to reach beyond our border and were to kill and maim persons overseas,” Morford said.