SAN JUAN, Puerto Rico - Former prisoners from the U.S. prison camp at Guantanamo Bay, Cuba, have organized a jailbreak in Afghanistan, kidnapped Chinese engineers and taken leadership positions with the Taliban, the U.S. military said Tuesday.

The former prisoners were released between 2002-2004 by claiming to be innocent or low-level figures, the military said in a statement, responding to questions about ex-prisoners who have allegedly resumed fighting.

The Pentagon gave brief descriptions of six detainees, including two it said were killed in fighting in Afghanistan, which the United States invaded to oust the Taliban regime following the Sept. 11, 2001 terrorist attacks in the United States.

The statement suggested the six were released from Guantanamo by mistake.

"These former detainees successfully lied to U.S. officials, sometimes for over three years,'' said U.S. navy Cmdr. Jeffrey Gordon, a Pentagon spokesman.

Last week, a Pentagon official, Joseph Benkert, testified to Congress that about 30 former prisoners have rejoined the fight against the United States. Other U.S. officials have made similar claims about prisoners at Guantanamo, where the military now holds about 380 men, mostly on suspicion of links to al Qaeda or the Taliban.

Guantanamo critics have been skeptical of the claims, saying it is part of a U.S. campaign to justify the detention of hundreds of men without charges at the remote base.

H. Candace Gorman, a Chicago-based lawyer for two Guantanamo prisoners, noted three of the names on the Pentagon list do not appear on official rosters of detainees. She said she believes they were never actually held at the prison in southeastern Cuba.

"To say detainees are back on the battlefield has become one of their justifications for indefinite detention,'' Gorman said.

"They have to justify the cruelty of what they're doing.''

The military said two of the men were killed in Afghanistan: Mohammed Yusif Yaqub, a commander of Taliban operations in southern Afghanistan who died in May 2004 while fighting U.S. forces, and Maulavi Abdul Ghaffar, a Taliban leader killed in a September 2004 raid by Afghan security forces.

A third man, Mohammed Ismail, was captured during an attack on U.S. forces near Kandahar.

The military also said Abdullah Mahsud, released in March 2004, was discovered after his release to have links to the Taliban and al Qaeda. He allegedly directed the kidnapping of two Chinese engineers in Pakistan in October 2004.

The other two on the list were Abdul Rahman Noor, who was released from Guantanamo in July 2003 and "has since participated in fighting against U.S. forces near Kandahar,'' and Mohammed Nayim Farouq, who "renewed his association with Taliban and al Qaeda members,'' after his July 2003 release.