Pictures of the Italian marines Massimiliano Latorre and Salvatore Girone and the colors of the Italian flag were projected on the Colosseum in Rome on Wednesda, in a show of support organized by the Rome municipality demanding the release of the two defence personnel.
The two marines have been arrested in India detained for fatally shooting two Kerala fishermen in February 2012.
Italy has insisted that the incident took place in international waters and hence the marines should be tried in Italy. But the Supreme Court in January ruled that the criminal case will be dealt in Indian courts.
A month later, the court allowed the men to travel to Italy for four weeks to vote in the national elections on the condition that they would return.
Tensions escalated when Rome announced that the marines would not be sent back. The Supreme Court imposed travel restrictions on the Italian ambassador and India threatened diplomatic action following which the two marines returned.
The return of the marines late last month has eased tensions between India and Italy. The duo are now set to face trial in a special court in Delhi.