A man in France who posted online about a deadly 2014 rampage in California has been taken into custody and has told police investigators he had been thinking about an attack of his own, the French prosecutor overseeing the police probe in Bordeaux said on Thursday.

French interior minister Gerald Darmanin posted on X, formerly Twitter, that police detained “an individual planning violent action during the passage of the Olympic torch relay in Bordeaux”.

It was not clear what the man’s plan and possible target were.

Linked to the minister’s tweet was a French media report saying that the 26-year-old man was suspected of planning “a mass killing” on Thursday, when the Olympic flame was passing through the Bordeaux region to finish in the city itself, its latest leg in a months-long trek ahead of the opening of the Paris Olympics on July 26.

But Bordeaux prosecutor Frederique Porterie, in a statement sent to The Associated Press, said that although the detained suspect “admitted to having considered committing an act” following an attack he himself had been a victim of, the man seemingly had not decided on a possible target.

“No reference to the Olympic flame was mentioned,” the prosecutor said.

“According to those close to him, he is very psychologically fragile. However, the appointed psychiatric expert did not reveal any particular disorder,” she wrote.

She identified the man with his first name and an initial, Alex G, and said he lives in the Bordeaux region and has no criminal record.

He was detained on Tuesday after he was flagged over what the prosecutor described as “a worrying message” online that referenced multiple slayings in Santa Barbara, California, on May 23, 2014, when Elliot Rodger, 22, killed six University of California students and himself.

The Bordeaux prosecutor said police investigators found evidence that the detained suspect was interested in a misogynistic online group known as “incels” or “involuntary celibates”, who sometimes call for violence against women.