Italy prosecutors open terrorism probe into oil tanker blasts

MILAN (Reuters) - Italian authorities opened a terrorism investigation into explosions last weekend that damaged an oil tanker off northern Italy, in the latest of four such incidents in the Mediterranean and Baltic seas in the past month, the chief prosecutor of the city of Genoa said on Thursday.

Two explosions blew a hole below the waterline of the Greek-operated crude oil tanker Seajewel, while it was anchored on Saturday off the port of Savona-Vado and discharging oil.

It was not immediately clear who was responsible for the alleged attack on the Seajewel, which, like the other tankers hit by explosions, had recently called at a Russian port.

"We took over the black box, the ship was not seized," Genoa chief prosecutor Nicola Piacente told Reuters in reference to Saturday's explosion on the Seajewel.

The anti-terrorism section of Genoa's Public Prosecutor's Office is investigating suspected "shipwreck aggravated by terrorist intent", he said.

The tanker's Athens-based operator, Thenamaris, said routine cargo operations were suspended on February 15.

"All crew on board the vessel and the third-party individuals involved in the cargo operations are safe, and there has been no harm to the environment as a result of the incident," Thenamaris said, adding that it was cooperating with local authorities in the investigation.

"The vessel remains ready to resume its cargo operations."

Lawmakers from Italy's opposition 5-Star Movement described the incident as "terrorist in nature" and called for a report to be submitted to parliament once the investigation was over.

Three oil tankers have been damaged by blasts in the last month in separate incidents around the Mediterranean, with the causes unknown.

All three vessels had recently called at Russian ports, according to ship tracking data and sources.

The Seacharm tanker, also operated by Thenamaris, was among the vessels damaged in these incidents.

Thenamaris said on Thursday Greek authorities were investigating what happened to the vessel in an incident which took place in January.

"The vessel (Seacharm) is currently undertaking normal operations," Thenamaris said.

A fourth tanker, the Koala, was damaged and stuck in the Russian Baltic Sea port of Ust-Luga.

Shipping industry officials have said there was growing concern over the incidents.

Maritime security officials and shipping sources monitoring the situation said on Thursday the most likely scenario was that seaborne limpet mines were the main cause of the blasts, adding that still needed to be confirmed.

One of the sources said it was likely that the Seajewel and Seacharm were hit by something external.

"It was an external strike, something external ... caused the damage," the source said.

Russian cargo ship Ursa Major sank in the Mediterranean Sea off Spain in late December after an explosion ripped through its engine room and two of its crew were missing, the Russian Foreign Ministry said last month.

(Reporting by Emilio Parodi, Jonathan Saul and Renee Maltezou, editing by Giles Elgood and Keith Weir)