SAN SALVADOR, FEB. 18 -- A prisoner who admitted being a leftist rebel and participating in the October murder of a prominent human rights leader retracted his confession today, saying he had been threatened.

"My confession in matters relating to this case was not true," said Jorge Alberto Miranda in a handwritten statement to the First Criminal Court. "The actions taken against me and my family pressed me into taking responsibility for actions I did not commit."

If Miranda was not involved in the killing, it would be a serious embarrassment for President Jose Napoleon Duarte and the security forces. In January, Duarte, in a nationally televised press conference, said Miranda and other leftist rebels were responsible for the October murder of Herbert Ernesto Anaya, president of the left-leaning, nongovernmental Human Rights Commission.

The rebels denied the charge. The family of Miranda and the commission he led said the killing was the work of right-wing death squads tied to security forces. The killing set off a week of domestic and international protests.

Duarte said he was "absolutely certain" no torture or coercion had been used to get Miranda to confess.

Defense attorney Leonardo Ramirez, who presented the statement, said the National Police had threatened Miranda and his family if the 19-year-old student did not collaborate and confess to participating in the assassination.

Ramirez said Miranda would give details, including the reported involvement of two Venezuelan intelligence agents, if allowed to make a new statement to the court.

In the last week the government has launched a campaign in the local press, using documents reportedly captured from the guerrillas, to indicate Anaya was killed by the rebels because they no longer trusted him. The government also said the rebels were pressing Miranda to retract his confession by threatening his family.

Both sides in the bloody civil war have put out exaggerated or fabricated reports of abuses by the other side, making it difficult to know the truth in many cases.

Miranda, in Mariona prison, was to appear before the judge today, but the prosecution filed a motion to block him from appearing.

Prosecutor Luis Roberto Pineda said the move by Miranda and his lawyers was a tactic designed to confuse public opinion, and that only the initial judicial confession was valid in court, not amended versions. Miranda, in interviews with the international press following his arrest, said he had provided cover for the man who killed Anaya, and said he was a member of the guerrillas.

He said repeatedly in the interviews he was not tortured, but said he was given two injections, reportedly for his tonsils, and that he was blindfolded for extended periods while being interrogated.

In his statement to the court, Miranda said he gave his confession because "I felt bad, very sick because of the treatment I received from the National Police. I felt bad since a doctor arrived, and while I was blindfolded, gave me a shot, saying it was for my tonsils.

"This appeared very strange to me because I have never had problems with my tonsils," Miranda added.

Many human rights workers and Miranda's family argued from the beginning that Miranda was tortured into confessing. Miranda's family says Miranda was asleep at the time the killing took place.

{On the third day of a rebel offensive, the Salvadoran military said nine guerrillas and three soldiers were killed in northern Chalatenango province and sabotage attacks left more than 60 percent of the country without electrical power, Reuter reported.}