"Certain indications that come from New Delhi about the legal proceedings against our marines leave me dumbfounded and outraged," Bonino said.
"Our commitment to bring home Massimiliano Lattore and Salvatore Girone is stronger than ever," she was quoted as saying in the Italian media yesterday.
Her remarks came in the backdrop of Home Ministry giving sanction to National Investigation Agency (NIA) to prosecute the Italian marines under the new provision of the Suppression of Unlawful Acts against safety of Maritime Navigation And Fixed Platforms on Continental Shelf Act (SUA).
The SUA carries the death sentences. But India last week spared them from the possibility of getting death penalty by asking the NIA to dilute the charges against them from murder to violence.
"An eventual request for the SUA act to be invoked on the two marines, if it should be confirmed, will be challenged in court by the Italian defence in the strongest terms," Agenzia Giornalistica Italia news agency quoted Bonino as saying.
Bonino's remarks came ahead of tomorrow's hearing of the case by Supreme Court, which asked Indian authorities to resolve all disputes arising out of the issue of invoking an anti-piracy law against marines.
Earlier, using strong words she had said the two Italian marines facing trial are "neither terrorists nor pirates".
The Marines, who were on-board Italian vessel 'Enrica Lexie' and are now lodged in New Delhi's Italian Embassy premises, allegedly shot dead the two fishermen on February 15, 2012 off Kerala coast.
The marines, deployed on the Italian-flagged oil tanker MT Enrica Lexie, have said they mistook the fishermen for pirates.
They are now staying in the Italian embassy in New Delhi awaiting trial. Rome wants the marines to be tried in Italy, claiming the incident took place in international waters.
However, New Delhi said it has the right to try the Italian personnel as the victims were Indians on board an Indian fishing boat. The case has strained ties between the two countries.