The president of Tunisia will address the nation, two days after a gun attack at a Tunis museum killed 23 people, mostly foreign tourists.
The authorities have already announced that the army is being sent to protect large cities, and aircraft, ships and drones will safeguard maritime traffic.
Islamic State has said it was behind the attack on the Bardo museum.
Nine people have been arrested following the attack in the capital on Wednesday.
The presidency has said four of those arrested were directly linked to the attack and five had “ties to the cell”.
President Beji Caid Essebsi will address his citizens on the day they mark 59 years since their independence from France.
Two cruise ships that had carried passengers killed or injured in the attack have arrived in Spanish ports.
Twenty of the people killed at the Bardo museum were foreign tourists.
Five of them were passengers from the Costa Fascinosa cruise ship.
Belgian tourist Karin Dons said she was not at the museum at the time of the attack but heard the shootings. She said she did not realize what had happened until she returned to the ship and saw the reports on television.
“Then you realize [what] you escaped from but other people are not lucky,” she said on leaving the ship in Barcelona.
Islamic State has said it was behind the attack on the Bardo museum, in an audio message in which it praised two “knights of the caliphate”.
Tunisian security official Rafik Chelli said the gunmen – identified as Yassine Laabidi and Hatem Khachnaoui – had slipped out of Tunisia in December and received weapons training in Libya ahead of the attack.
He told the el-Hiwar el-Tounsi TV channel that authorities did not have details about where or with which group they had trained.
The men were killed as security forces stormed the museum.
Tourists from Japan, Colombia, Australia, the UK, and several other European countries were killed in the attack and more than 40 people were injured.
French Interior Minister Bernard Cazeneuve is travelling to Tunis on a pre-scheduled visit coinciding with the country’s Independence Day holiday.
Source: BBC