DETROIT -- A Nigerian man charged with trying to blow up an international flight near Detroit on Christmas fired his lawyers Monday and suggested he wants to plead guilty to some of six charges against him.

U.S. District Judge Nancy Edmunds advised Umar Farouk Abdulmutallab not to get rid of his attorneys, but he insisted. Edmunds then granted his request and asked if he had anything further to say.

"If I want to plead guilty to some counts ... basically, how would that go?" Abdulmutallab responded during his first court appearance since being arraigned in January on charges that include attempted use of a weapon of mass destruction.

Edmunds told him she couldn't advise on such matters and ordered that a stand-by attorney be named to assist Abdulmutallab with his defense. Stand-by attorneys are permitted to listen and give advice, but they don't negotiate with the government or take an active role in a trial.

Asked for comment, Miriam Siefer, who was the head of Abdulmutallab's defense team, said: "Mr. Abdulmutallab has the right to represent himself, and he's exercised that right."

Passengers who saw flames pounced on Abdulmutallab, subdued him and forced him to the front of Northwest Airlines Flight 253 as it approached Detroit on Dec. 25. Authorities say he was trying to set off explosives in his underwear.

The incident exposed flaws in security and intelligence. Abdulmutallab's father warned the U.S. Embassy in Nigeria that his son had drifted into extremism in Yemen, but he never was added to the "no-fly" list, which would have kept him off the plane.

The White House in January said the U.S. government had enough information to potentially disrupt the plot by al-Qaida in the Arabian Peninsula but failed to connect the dots.

Abdulmutallab has not been silent while in custody. In February, law enforcement officials said he had turned against Anwar al-Awlaki, the U.S.-born Yemeni radical who claims to be his teacher, and had helped the U.S. hunt for him.

Edmunds said the yet-unnamed stand-by counsel would appear with Abdulmutallab at a court conference scheduled for Oct. 14.