Italian anti-terrorism police on Wednesday arrested a Lebanese national of Palestinian descent on suspicion he was planning a poison attack in the Sardinian town of Macomer.
"He was planning an attack with ricin and anthrax," chief anti-terrorism prosecutor Federico Cafiero De Raho told reporters, naming the man as Alhaj Ahmad Amin.
Amin, 38, who is a legal immigrant and married with three children, was arrested in Macomer earlier in the day by hooded police who forced him from his car as he left home.
It was not immediately possible to contact Amin and the name of his lawyer was not released.
Police said they had been tracking him since September following a tip-off from Lebanon, where his cousin had been arrested after trying to poison a water tank used by the army.
A police official said Amin had tried to buy poison over the internet, but it was not clear if he had succeeded.
Information about poisons and the Islamic State group was found on his mobile phone.
Amin had recently withdrawn all his money from the bank and was searching for his passport, Cafiero De Raho said: "He must have been close to doing something."