GUANTANAMO BAY NAVAL BASE, Cuba (AP) — A former Maryland resident pleaded guilty Wednesday to helping al-Qaida plot attacks from his native Pakistan, reaching a plea deal with the U.S. government that limits his sentence but that his lawyers say could put him and his family in jeopardy.

A lawyer entered the plea on behalf of Majid Khan at the U.S. base in Cuba. Asked by the judge if he understood the plea, Khan answered in English, “Yes, sir.”

The plea deal, the first reached by one of the so-called “high-value” detainees at Guantanamo, says Khan, 32, can serve no more than 25 years in prison. But he is required to cooperate with military prosecutors as they build cases against other prisoners, a fact that defense lawyers wanted kept confidential.

Wells Dixon, one of his civilian lawyers, said Khan feared for the safety of family members in the United States and abroad. “There is a specific, historical basis for the concern,” he told the judge in arguing to keep the pre-trial agreement sealed.

The military judge, Army Col. James Pohl, rejected the request, saying the fact that he had agreed to cooperate was already in the public domain.

Khan is the seventh Guantanamo prisoner to be convicted of war crimes and he is considered the most significant. He is the first prisoner who was held in clandestine CIA custody overseas and in the top-secret section of the U.S. base in Cuba known as Camp 7 to plead guilty.

His appearance Wednesday, dressed in a dark blazer and tie and with neatly trimmed hair and beard, was the first time he has been seen in public since his capture in March 2003.

Prosecutors said Khan plotted with the self-proclaimed mastermind of the Sept. 11 attack, Khalid Sheikh Mohammed, to blow up fuel tanks in the U.S., to assassinate former Pakistani President Gen. Pervez Musharraf and to provide other assistance to al-Qaida.

As part of the agreement, Khan’s sentencing will be postponed for four years, during which he is expected to provide testimony against other detainees.

Khan moved to the U.S. with his family in 1996 and was granted political asylum. He graduated from Owings Mills High School in suburban Baltimore and worked at several office jobs as well as at his family’s gas station.

Military prosecutors say he traveled in 2002 to Pakistan, where he was introduced to Mohammed as someone who could help al-Qaida because of his fluent English and familiarity with the U.S. Prosecutors say that at one point he discussed a plot to blow up underground fuel storage tanks.

Prosecutors say Khan later traveled with his wife, Rabia, to Bangkok, Thailand, where he delivered $50,000 to the Southeast Asian terror group Jemaah Islamiyah, an al-Qaida affiliate, to help fund the Aug. 5, 2003, suicide bombing of the J.W. Marriott hotel in Jakarta, Indonesia. The attack killed 11 people and wounded at least 81 more.

The U.S. military holds 171 prisoners at Guantanamo, and officials have said about 35 could face war crimes charges.