Candidates weigh in on Guantanamo charges

WASHINGTON (Reuters) - Those responsible for the September 11 attacks should be brought to justice but the military tribunals at Guantanamo Bay must be "above reproach," Democratic presidential candidate Barack Obama said on Monday.

The front-runner for the Republican presidential nomination, Arizona Sen. John McCain, said charges against the alleged conspirators were long overdue.

"This is something that should have, in my view I'm sorry that it's taken so long. Let's begin this process," McCain said.

After the Pentagon announced charges against the alleged mastermind of the attacks and five other Guantanamo detainees, Obama repeated his view that civilian courts and the traditional military courts martial system were best suited for handling such cases.

The charges against Khalid Sheikh Mohammed and five others imprisoned at the U.S. detention center at Guantanamo Bay, Cuba, include conspiring with al Qaeda to attack and murder civilians and 2,973 counts of murder for those killed.

"Of course, we should ensure that the planners and perpetrators of 9/11 are brought to justice, and the death penalty is appropriate for whomever committed such heinous crimes. But these trials will need to be above reproach," Obama said.

"These trials are too important to be held in a flawed military commission system that has failed to convict anyone of a terrorist act since the 9-11 attacks and that has been embroiled in legal challenges," he added.

McCain, a former Navy pilot who spent five years as a Vietnam prisoner of war, has campaigned hard on the theme of fighting Islamic radical extremism. He has vowed to capture al Qaeda leader Osama bin Laden if he has to follow him to the "gates of hell."

(Writing by JoAnne Allen; editing by Patricia Zengerle)