39 people are said to have been rescued after the accident.
The submarine is said to have sunk near a harbor in the tourist resort of Hurghada.
A local governor reports that passengers on the submarine were from Russia, India, Norway, and Sweden.
"The Ministry of Foreign Affairs has information that there may have been Swedish citizens on board the submarine, but currently has no knowledge of any Swedes being among the deceased", the Ministry of Foreign Affairs writes in an email to TT and adds that the embassy in Cairo is in contact with local authorities.
Four seriously injured
According to the Ministry of Foreign Affairs, it is not certain that a distressed Swedish citizen will become a case for the department, as those affected do not always choose to seek consular support through the embassy in the country.
Earlier, the Russian Embassy in Egypt stated on social media that all 45 passengers were Russian. Several of them were children, according to the embassy's post.
According to the state-owned Egyptian newspaper Akhbar al-Yom, six people have died and nine have been injured, four of them seriously.
The cause of the accident is still unclear, Egyptian authorities say the incident is being investigated.
Ticket sales stopped
The travel company Tui has decided to stop all sales of tickets to submarine tours, which were previously available for booking on the company's website.
When we found out about the accident, we stopped selling the tickets, says Anna Mörk-Löwengreen at Tui's press department, to Aftonbladet.
Last November, eleven people died on a tourist boat in the Red Sea off Hurghada. Egyptian authorities then reported that the boat had been hit by a large wave, while several survivors claimed that there were safety deficiencies on the boat.
The submarine Sindbad has been taking tourists on tours in the Hurghada area for several years. During the tours, tourists are taken down to 25 meters below sea level to see coral reefs and other marine life.
