Tunisia has arrested a "significant number" of suspects in the terrorist attack on foreign tourists at the beach resort of Sousse that killed at least 38 and injured dozens, Interior Minister Mohamed Najem Gharsalli said on Monday.
Gharsalli said "the first part of the network" responsible for the gun attack at the beachfront Imperial Marhaba Hotel had been detained, local Radio Shems Fm reported.
"We have begun with the arrests of a first group, a significant number of people belonging to the network behind this criminal terrorist," Gharsalli said.
He was referring to the 23-year-old Tunisian engineering student Seifeddine Rezgui who was shot dead by police after he allegedly carried out the massacre in Sousse with a Kalashnikov rifle, disguised as a tourist.
The bodies of victims of the attack were still being identified on Monday but most of the victims were British, the Tunisian government said.
An alleged accomplice of Rezgui was arrested hours near the motorway from Sousse to Tunis, two hours after the massacre. Police recovered Rezgui's mobile phone from the sea and said they hoped to be able to retrieve information from its SIM card.
"We will uncover all those involved," Gharsalli warned.
He gave no further details but said investigators were probing the possibility that Rezgui and accomplices in the attack were trained in neighbouring Libya.
Earlier on Monday, Tunisia said 1,000 armed officers would be deployed from July 1 to reinforce the country's tourism police, who will also now carry guns for the first time.
Tunisian authorities also announced plans to close 80 mosques accused of inciting extremism, and Algeria said it was deploying 25,000 soldiers and raising security alert levels along its 965 km border with Tunisia.
IS claimed the shooting, the worst in modern-day Tunisia, which followed a March attack also claimed by the group on Tunis's Bardo National Museum that killed 21 foreign tourists and a policeman.
IS also took credit for the Bardo attack, which Tunisian authorities said they believe it was carried out by another jihadi group, Okbn Ibn Nafaa.
