Authorities in Tunisia have confirmed a number of arrests have been made over a beach massacre that left 38 people dead in the country's worst jihadist attack.

The interior ministry says those arrested include a significant number of people from the gunman's network.

The massacre, claimed by the Islamic State group, was the deadliest for Britain since the 2005 London bombings, and there are fears it could inflict a devastating blow to Tunisia's vital tourism industry.