LONDON - U.S. Homeland Security Secretary Michael Chertoff said yesterday that President-elect Barack Obama should not rush to close Guantanamo Bay before he has a plan to deal with all detainees.

In an interview with BBC television, Chertoff said that Obama must work out how to prosecute detainees, particularly those who can't be sent back to their own countries for trial, before he closes the facility.

"The problem is what do you do with the people in Guantanamo? Regrettably, some who have been released turn up on the battlefield again," Chertoff told the BBC. "We had a suicide bomber who was released and then blew himself up in Iraq."

"My advice would be to take a deep breath and try to put together a plan that would sort between the various categories of detainee," he said.

Obama has pledged to close the prison camp, where 250 men are detained, but has not specified how and where the detainees will be moved or prosecuted.

"Some, I think, can be sent back, and we've been doing that. Some will not be able to be sent back, and we need to have a legal process to resolve their cases in a way that is fair to them," Chertoff said.

Chertoff said that prosecuting detainees in U.S. civilian courtrooms may prove impractical because of complications over evidence that has national security implications.

Critics say that military trials at Guantanamo lack legitimacy because of political interference and rules that allow coerced and hearsay evidence. Some family members 9/11 victims have said they do not believe the trials are fair or capable of achieving justice.