President Clinton offered an anmnesty to 16 former members of the Armed Forces of National Liberation (FALN).

All had been imprisoned on sedition and weapons convictions in support of the FALN, a pro-independence group blamed for 130 bombings in the United States that killed six people and wounded dozens of others from 1974 to 1983.

Fourteen accepted, and 11 of those were released from prison last week.

Executive privilege

"With the legal advice of the attorney general, the president is invoking executive privilege over certain documents and testimony relating to the grant of clemency," said Jim Kennedy, spokesman for the White House counsel's office.

Some 10,000 pages of documents related to the decision, including thousands of letters calling on the president to show leniency toward the prisoners, will be handed over to Congress.

Republican Rep Dan Burton, Chairman of the House Government Reform Committee, was being informed of the president's decision in a letter from White House Deputy Counsel Cheryl Mills.

Committee officials have threatened to seek contempt charges if they were not satisfied with the administration's response to its subpoenas.

The Senate Judiciary Committee also plans to issue subpoenas for the documents.

Boost for Hillary? President Clinton's decision led to accusations that he was using the clemency ruling to boost his wife Hillary's Senate ambitions.

New York, where Hillary Clinton is to be the Democratic candidate, is home to 1.3 million Puerto Ricans.

Republican presidential contender Steve Forbes called the amnesty a "terrorists-for-votes deal".

Mrs Clinton opposed the clemency deal, however, after it began to draw criticism, and then was herself criticised by some prominent Puerto Ricans in New York.

President Clinton extended the offer after a lengthy review by the White House's former Chief Counsel, Charles Ruff.

Prominent human rights advocates, including South African Anglican Archbishop Desmond Tutu and former President Jimmy Carter, backed the move.

But there has also been strong sentiment against the president's decision. At a Senate hearing, two retired FBI agents who investigated the FALN characterised its members as terrorists.

Reverend Jesse Jackson has questioned the timing of the amnesty, alleging that it was an attempt to undermine a demand for an end to US military exercises on Puerto Rico's populated island of Vieques.

There has been widespread opposition in Puerto Rico over the US Navy's use of live-bombing exercise, especially since the killing of a security guard inside the firing range in April, when two 500-pound bombs were dropped by a Navy jet that missed its target by more than a mile.