MADRID — A Spanish judge on Thursday ordered a former Salvadoran colonel jailed while he awaits trial for alleged involvement in the killing of five Jesuit priests in 1989.

Inocente Orlando Montano, who served as vice minister for public security in the 1980s during El Salvador’s civil war, was extradited to Spain from the United States on Wednesday.

The 74-year-old faces charges of terrorist murder and crimes against humanity in the killings of Father Ignacio Ellacuria and four other priests of Spanish nationality. Another Jesuit, their housekeeper and her daughter were also killed in a case that sparked international outrage.

According to U.S. court documents, the priests were helping to organize peace talks during the 1980-1992 conflict in the Central American country that killed 75,000 people. Ellacuria was at the time the dean of UAC, a Salvadoran university.

Montano has denied involvement in the killings. His Spanish lawyer, Antonio Alberca, requested on Thursday for his client to be freed on medical grounds because of his weak condition after having suffered bladder cancer.

The former colonel arrived at the National Court in Madrid by ambulance and appeared before magistrate Manuel Garcia-Castellon in a wheelchair.

But the judge on Thursday upheld a 2011 decision to preventively jail Montano, saying there was a risk for him to flee.

The magistrate also said that the Spanish probe into the killings showed that the former colonel “took active part in the decision and design of the assassinations” as one of the leading members of La Tandona, a group of 20 Salvadoran military officers.

Montano, who oversaw the National Police as vice minister of public security, attended a key meeting on Nov. 15, 1989, in which a decision was made to murder Ellacuria on the following day and, according to the Spanish probe, “to make sure that there were no witnesses.”

Montano was arrested in 2011 in Massachusetts, where he had been working at a candy factory, and sentenced to nearly two years for immigration fraud and perjury.

A lengthy legal battle over his extradition then unfolded, with a federal magistrate ruling in 2016 that evidence showed that Montano had taken part in the plot, and the U.S. Supreme Court removing the final legal hurdle to his extradition earlier this month.

Spain has also issued warrants in an effort to try other former officers who are currently living in El Salvador, but the Central American country declined to allow their extradition.

While two officers served short sentences in El Salvador, Montano and other high-level officials were never tried by Salvadoran authorities in the priests’ killings. A Jesuit group recently began efforts to have Salvadoran authorities re-examine the killings.

Montano has been summoned to testify before the judge in Madrid next week as part of preparations for a trial.