A Mexican chemistry student accused of plotting a gas attack on protesters against Pope Benedict XVI in Madrid will appear in court today, a legal official said.

The 24-year-old Mexican, in Spain on a student visa, was one of about 30,000 volunteers helping in the August 16-21 World Youth Day celebrations in Madrid, the official said on Tuesday.

He is to face the National Court today, the same day the 84-year-old head of the Roman Catholic Church arrives for the final four days of festivities by more than a million pilgrims in Spain’s capital.

Mexican embassy spokesman Bernardo Graue identified the suspect as Josè Alvano Perez Bautista.

Consular officials had visited him in jail, he said.

“They confirmed that he is in good medical condition, that he has a duty lawyer and that he has received good treatment from the Spanish authorities,” the spokesman said.

Police said in a statement released on Tuesday that the arrested man was suspected of planning an attack with “asphyxiating gases” and other chemicals against the protesters.

Officers had seized the suspect’s laptop, portable memory, and two notebooks containing notes about chemicals unrelated to his studies. But they made no mention of chemicals or equipment being taken.

“The arrested man is the suspected author of planning for an attack with asphyxiating gases and other chemical substances against participants in protests against the visit of His Holiness Benedict XVI,” police said.

The daily El Païs said police had no proof that the suspect was capable of carrying out an attack but wanted to avoid even the chance of a failed attack that might panic people.

It said police were tipped off by people who found the man’s comments on internet fora in which the student said that he could not allow protests against the Pope.

The man studied at the Spanish Research Council’s organic chemistry institute, police said.