Seventeen people, including a number of British nationals, are missing after a tourist boat on a diving trip capsized in the Red Sea.

The Sea Story was carrying 31 tourists from several countries and 14 crew when it sent a distress signal at 5.30am local time, according to a statement from Egypt’s Red Sea governorate.

It was not immediately clear what caused the four-deck, wooden-hulled motor yacht to sink.

So far 28 people have been rescued, leaving 17 people missing.

The British Foreign Office confirmed it was providing consular support to a number of British national and their families after the incident.

The boat left Port Ghalib, near Marsa Alam in Egypt, for a diving trip that was due to finish on Friday in the town of Hurghada, 124 miles (200km) north.

The governor, Amr Hanafi, said some survivors had been rescued by an aircraft, while others were transported to safety onboard a warship.

“Intensive search operations are under way in coordination with the navy and the armed forces,” Hanafi said.

Authorities have not indicated the possible cause of the incident or issued a breakdown of the nationalities of the missing people. According to unverified local media reports, those onboard included four Britons, four Germans, five Spaniards, two Belgians, three Slovaks and two Americans.

The area of Marsa Alam has had at least two similar incidents this year. Both ended without any deaths.

The Red Sea coast is a popular tourist destination in Egypt, a country of 105 million people that is in the grip of an economic crisis. Nationally, the tourism sector employs 2 million people and generates more than 10% of GDP.

This month, 30 people were rescued from a sinking dive boat near the Red Sea’s Deadalus reef.

In June, 24 French tourists were safely evacuated before their boat sank in a similar accident.

Last year, three British tourists died after a fire broke out on their yacht, engulfing the vessel in flames.

Dozens of diving boats make trips between coral reefs and islands off Egypt’s eastern coast every day. Safety regulations are known to be robust but unevenly enforced.