Italy is seeking more information on a failed rescue operation in Nigeria, in which an Italian and a British hostage were killed.
Franco Lamolinara and Chris McManus were kidnapped in Nigeria last May and were killed as a rescue team sought to save them yesterday.
British Prime Minister David Cameron announced their deaths and took responsibility for authorising a rescue.
Italian Prime Minister Mario Monti has asked Nigerian President Goodluck Jonathan to provide "a detailed reconstruction" of the events leading to the deaths of the two men.
But former Italian prime minister Massimo d'Alema criticised the attempted rescue operation, which he said was apparently mounted without Italy being notified.
Mr d’Alema is now in charge of a parliamentary committee dealing with security issues.
Speaking on BBC's Newsnight programme, Italian Senator Lucio Malan also wanted to know why the Italians had not been consulted.
"It is quite uncommon that a country that is involved is not informed before. Apparently it was a very difficult situation and it might have been the best decision but it is still to be explained why the Italian authorities haven't been informed," he said.
Mr Lamolinara and Mr McManus were killed in far northwestern Nigeria, Nigeria's president said, and residents reported an hours-long shootout in an area of the city of Sokoto at a building under construction, though authorities have not confirmed details.
British media are reporting that the mission was led by elite British special forces, citing unnamed government sources.
Mr Cameron said he had given the go-ahead for a rescue after "credible information" was received about the location of Chris McManus and Franco Lamolinara.
He said the Nigerian authorities, with British support, had launched the attempt to rescue the men after "a window of opportunity arose to secure their release".
"It is with great regret that I have to say that both Chris and Franco have lost their lives.
"We are still awaiting confirmation of the details, but the early indications are clear that both men were murdered by their captors, before they could be rescued."
Nigeria's president blamed their deaths on Islamist group Boko Haram in a statement and said the killers had been arrested.
The two hostages were kidnapped by heavily armed men who stormed their apartment in the city of Birnin Kebbi in May 2011.
They had been helping build a central bank building in the city and worked for construction firm Stabilini Visinoni.
