All 21 passengers on a charter boat that sank in Italy's Lake Maggiore on Sunday, killing four people, were currently or formerly tied to Israeli and Italian and intelligence work, officials said.
The 16-meter (52-foot) houseboat had been carrying 23 people at overcapacity when an apparent waterspout struck nearby, causing it to capsize on Sunday evening, CNN affiliate Sky Tg24 reported.
Some of the party managed to swim ashore and others were rescued by nearby boats, according Sky Tg24, adding that, although five were taken to the hospital, none of the survivors sustained any serious injuries.
There were 13 Israeli and 8 Italian passengers on board at the time the boat sank, while the victims were two men and two women. The Italian victims were named as Tiziana Barnobi, 53, and Claudio Alonzi, 62, a delegate of the country's secret service confirmed, while a spokesperson for Israel's foreign ministry identified the Israeli victim as Erez Shimoni, 60.
The boat's captain, whose Russian partner Anna Bozhkova, 50, also died in the incident, is under investigation over the deaths, according to the Italian prosecutor.
Divers and a helicopter were also used as part of the search and rescue operation, the local fire service said. Authorities are trying to lift the boat from the lake after two failed attempts.
Italy's military police, the Carabinieri, are assisting with the investigation, the prosecutor's office told CNN.
"The prosecutor's office is not investigating the nature of the passengers on the boat, only the captain's role in the accident," the prosecutor's office confirmed.
The Israeli prime minister's office said on Wednesday that Israel's security forces lost a "dear friend" in the fatal boat accident. The body of Shimoni, who was a retired employee of the security forces, has been returned to Israel.
Shimoni had missed a flight on Sunday, along with another Israeli national, Israeli media reported, and the two were not expected to be on the boat, according to the local Italian prosecutor.
A delegate of the Italian secret service issued a public condolence "sharing closeness and pain for the tragic event to the families of the victims."
Lake Maggiore is a popular destination for tourists and is shared by Italy and Switzerland.
The boat, named "The Gooduria," had advertised as a charter vessel for €2,000 ($2,130) a day. Passengers had been reportedly celebrating a birthday party when the boat, traveling between the Italian towns of Lisanza and Dormelletto, capsized, according to Sky Tg24.