The retrial of the founder of Peru's Shining Path movement has been suspended after two of the three judges stood down.
Mr Guzman was defiant when the retrial first opened
Abimael Guzman faces charges of aggravated terrorism. Prosecutors have demanded a life sentence.
His group is blamed for the deaths of more than half of 70,000 people killed in the insurgency of the 80s and 90s.
Mr Guzman was sentenced to life in prison by a military court in 1992, but that conviction was quashed last year.
The BBC's Hannah Hennessy in Lima says he has confessed to leading Shining Path, but denies being a terrorist.
She adds that the state prosecutor had called for the removal of the judges, because of their involvement in previous rebel trials.
The trial of the 69-year-old former philosophy teacher, began 10 days ago in a high security naval base.
In his first court appearance, Mr Guzman and his supporters turned the court into a demonstration, shouting slogans and forcing the trial to be suspended.
On Monday, our correspondent says, the judges argued over their involvement in previous rebel trials.
Leading judge Dante Terrel refused a request by prosecutors to step down for having defended rebels before becoming a judge.
"I have not done anything to justify my stepping down in
this case," he said.
But another of the judges, Carlos Manrique, said he was withdrawing because of comments he had made about Guzman in an earlier case.
It then emerged that the third judge Jose de Vinatea had also been involved in that case, and he announced he would withdraw.
Shining Path in decline
Peru's top judge in terrorism cases said he would personally preside over the case, Reuters news agency reported him as saying.
Pablo Talavera, head of Peru's National Terrorism Court,
told CPN radio, the trial could restart in 30 days.
The Shining Path waged a bitter war against government troops, mostly in the Peruvian Andes, with a view to overthrowing Capitalism and imposing Communism.
Analysts say it has become a shadow of its former self since Mr Guzman was captured in 1992.
Our correspondent says it now has only a few hundred die-hard members, compared to several thousand in its prime.
Mr Guzman's earlier conviction was overturned by the country's constitutional court, which said the secret military court which tried him could not guarantee a fair trial.