NEW DELHI/ROME: Italy on Friday said it was important to suspend the diplomatic assurance on sending back its marines, accused of killing two Indian fishermen, as it needed to obtain assurances from India that the soldiers won't face death penalty.

Defending their initial decision not to send back their marines even at the cost of diplomatic breach of assurance, Italian deputy foreign minister Steffan de Mistura said death penalty was unacceptable and became an issue for the Italian government when the Supreme Court talked about setting up of a special court to try the soldiers.

He also said a special court should be established "as soon as possible" to try the marines stressing that Rome wanted "justice and clarity".

"During the bail, there was an indication that a special court would be established. That was the moment when the issue of death penalty became a crucial aspect in Italy," Mistura said here.

The minister, who escorted the two marines back to India in a special military plane just in time before the expiry of the Supreme Court-set deadline, said "according to Italian law, death penalty is an extremely serious aspect... was unacceptable legislatively and culturally in Italy".

"The solution was triggered by a letter from Indian authorities which was a very comprehensive letter and official letter guranting to the Italian authorities that in this case there is no question that death penalty could even be envisaged and at the same time the marines upon their return will have the same status that they had on their departure," he said.

"That was enough for the Italian government to take away the suspension, painful it might have been of the affidavit," he said.

India gave an assurance to Italy that the marines will not face death penalty nor will they be arrested, bringing to an end a raging 11-day diplomatic row between the two countries.

Row with India was 'necessary' to negotiate on marines: Italy

Italy on Friday said that a diplomatic row with India over the marines accused of killing two Indian fishermen was "necessary" to make sure the men did not face the death penalty.

"The situation is normalising," Italian foreign minister Giulio Terzi told La Repubblica daily after Italy's surprise climbdown last night in the row that saw Indian Supreme Court ordering the Italian ambassador not to leave the country.

The marines, Massimiliano Latore and Salvatore Girone , arrested in connection with the killing of the fishermen in February last year returned on Friday along with Italian deputy foreign minister Steffan de Mistura in a military plane.

Justifying their earlier decision not to send back the marines, who were given permission by the Supreme Court to come here to vote in the elections, Terzi said that without buying time for talks by reneging on the pledge to return the pair, "we would not have been able to negotiate the current conditions, which envisage (good) conditions of everyday living and the guarantee that the death penalty will not applied".

The Italian government, which had given an undertaking before the court that the marines will be sent back, had on March 11 sent a note verbale to the Indian government informing it that the two will not be sent back.

On January 18, the apex court had turned down the Italian government's plea that the Indian courts had no jurisdiction in the case and had held that the two marines should be tried by a special court constituted by the government.

The two marines were on board an Italian vessel 'Enrica Lexie' when they allegedly shot dead two fishermen off the Kerala coast on February 15, last year.