Tunisia has claimed to have "uncovered and destroyed" a group the government alleges was behind the deadly shooting at a seaside resort in the town of Sousse that has left at least 38 foreign tourists dead.
Kamel Jendoubi, a minister who heads a crisis group set up after the attack, said on Thursday that at least eight people were arrested in connection to the massacre.
"The security services have been able to... uncover and destroy the network that was behind this operation," said Jendoubi. "Eight people with direct links to the carrying out of the operation, including a woman, have been arrested."
The arrests came almost a week after Seifeddine Rezgui, a 23-year-old student, shot dead 38 foreigners after pulling a Kalashnikov assault rifle from a beach umbrella at the Port El Kantaoui resort in Sousse.
The massacre was the deadliest attack in Tunisia.
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After the attack - which was claimed by the Islamic State of Iraq and the Levant (ISIL) group - Tunisia's government pledged to boost security around hotels, beaches and attractions.
Jendoubi said 1,377 extra armed security officers had been deployed to reinforce police already on the ground.
Tunisia's President Beji Caid Essebsi admitted that security forces had not taken measures to protect beaches despite threats against tourists.
Friday's attack was the second on tourists in Tunisia claimed by ISIL in just three months, after the group said it was behind a March attack on the National Bardo Museum in Tunis that killed 22 people.
Tunisian authorities have said Rezgui received weapons training from rebels in neighbouring Libya, travelling to the chaos-wracked country at the same time as the two young Tunisians behind the Bardo attack.
In the past four years, dozens of police and soldiers have been killed in Tunisia in clashes and ambushes attributed to rebels - mainly in the western Chaambi Mountains.
Disillusionment and social exclusion have fuelled radicalism among young Tunisians, with the country exporting about 3,000 fighters to Iraq, Syria and Libya.