Six people have died and nine others are injured after a tourist submarine sank in the popular Egyptian Red Sea destination of Hurghada, two municipal officials said. AP reported that the officials were speaking on condition of anonymity because they were not authorised to brief the media.

The incident, involving a recreational vessel operated by Sindbad Submarines, occurred in waters opposite Hurghada’s Marriot Hotel resort. Citing municipal officials, Reuters and Associated Press reported that six foreigners, whose nationalities are still unknown, had died. It was not immediately clear what caused the submarine to sink.

The Russian embassy in Egypt has said that that all of the tourists on board the submarine were Russian. It said 45 passengers were on board the vessel, including children, in a Facebook post.

The local governorate’s office told Reuters that all of those confirmed dead were foreign citizens, while survivors had been ferried by ambulance to several hospitals in the city. Emergency crews were able to rescue 29 people, according to a statement released by the governorate. Many tourist companies have stopped or limited travelling on the Red Sea due to the dangers from conflicts in the region.

The Sindbad club’s website says it offers short tourist trips in two submarines that it operates that have a maximum depth range of 25 metres. According to the website its submarines allow tourists to “experience the beauty of the Red Sea’s underwater world without getting wet”.