The accident occurred less than a mile off the coast of Hurghada during an underwater excursion to see the coral reef, according to the Russian consulate in Hurghada.

At least six people are believed to be dead and another nine injured — six critically — after a tourist submarine sank off of Egypt’s Red Sea coast Thursday.

Tourist submarine sinks in Egypt’s Red Sea, killing six people near Hurghada. The tragedy raises urgent concerns about safety in underwater tour operations.