Italy welcomed India's decision to release an Italian tanker held for over two months, said Italian Foreign Minister Giulio Terzi on Wednesday, saying it was "a first step" towards a comprehensive settlement of the affair.

Italy's "diplomatic efforts with the Indian authorities would continue on all levels," Terzi said in a statement, after two Italian marines currently detained in the southern Indian city of Thiruvananthapuram for allegedly killing two local fishermen were allowed to leave India.

Earlier on Wednesday, Indian supreme court ordered the release of the tanker Enrica Lexie, with its 24 crew onboard, on condition that the shipping company and Italian government ensure the availability of the vessel and crew in case they are required for ongoing investigations.

The tanker will leave Indian waters as soon as it has completed some paperwork to satisfy the requirements of Indian authorities, the lawyer for Italy, Deljeet Titus, said.

The Enrica Lexie was held in India since February 15, when the two Italian guards Massimiliano Latorre and Salvatore Girone were arrested after allegedly shooting dead two local fishermen off the southern state of Kerala, reportedly mistaking them for pirates.

The deaths have sparked a diplomatic dispute between the two countries. In the past weeks, many Italian officials have made multiple visits to mount pressure on the Indian authorities.

According to Rome, Italy should have jurisdiction for the case, as the two marines were working on an anti-piracy mission aboard a vessel in international waters.

The Indian supreme court has admitted Italy's jurisdiction plea and set a May 8 date for the first hearing.