-- An Italian prosecutor said Wednesday that he had provided U.S. authorities with transcripts of phone calls between terror suspects, including one transcript that reportedly refers to a woman ready to carry out a chemical attack in the United States.

Two terror suspects were arrested late Monday in Milan, including Rabei Osman Sayed Ahmed, an Egyptian believed to have been behind the March 11 train bombings in Madrid, said Milan prosecutor Maurizio Romanelli.

In one of the intercepted conversations, Ahmed refers to a woman ready to carry out a chemical attack in the United States, the ANSA news agency reported.

When asked about the content of the transcripts, Romanelli pointed to news reports that mention the alleged chemical plot. He did not dispute the reports, but he said he would not comment further on the content of the wiretaps.

The wiretaps refer to "small groups ready to carry out suicide attacks," he said. In most cases, the likely location of the attacks was Iraq, he said. The prosecutor gave no further details.

Police arrested Ahmed, along with the man he was staying with, a Palestinian identified as Yahia Payumi.

Viviana Bossi, defense attorney for the two suspects, said Wednesday that her clients were unclear about the exact charges against them. "They deny they are terrorists," she said.

Authorities say Ahmed is a key suspect in the Madrid attacks. Investigators have blamed the bombings, which killed 191 people, on Islamic radicals with possible links to Osama bin Laden's al Qaeda network.

Italian officials suspect that Ahmed was planning further attacks, and they tipped off Belgian counterparts who arrested 15 people late Monday and early Tuesday in coordinated raids. At least one of the 15 -- most of them Palestinian, Jordanian, Moroccan and Egyptian -- had been in contact with Ahmed, Romanelli said.

The AGI news agency reported Wednesday that the suspects might have been planning an attack on the Paris subway system. Ahmed was recorded asking one of those arrested in Belgium about the Paris Metro and security there, AGI said, citing police sources.

Asked about a report in the Milan daily Corriere della Sera that the suspects were planning an attack against a NATO base in Belgium, Romanelli said investigators had no information on specific targets.

In Spain, police arrested six Spaniards in the northern Asturias region Wednesday and accused them of supplying the dynamite used in the Madrid attack. The suspects included the security guard of a coal mine from which the 440 pounds of explosives used in the bombings were stolen, Interior Minister Jose Antonio Alonso said.