Nine Islamist militants were killed by Tunisian forces hours before a solidarity march began in the capital, Tunis, earlier today.
The "Le Monde est Bardo" (The World is Bardo) protest is being held to condemn extremist violence following a terrorist attack on the country's Bardo museum earlier this month.
The security operations took place in the southern Gafsa region and was aimed at militants from a local al-Qaeda affiliated group known as Okba Ibn Nafaa Brigade.
One militant was named as Lokman Abu Sakhr, an Algerian who was accused of playing a part in the Bardo attack that has left 24 people dead.
"We have killed most of the leaders of Okba Ibn Nafaa who were behind many recent attacks," said Tunisian Prime Minister Habib Essid. "This is a clear and strong response to the terrorism after the Bardo attack."
Earlier, a statement from the French president's office confirmed that a fourth French national, Huguette Dupeu, had died, becoming the country's fourth casualty.
Thousands of Tunisians and global leaders including French President Francois Hollande, Italian Prime Minister Matteo Renzi and Palestinian leader Mahmoud Abbas are participating in the march.
The demonstration started at Bab Saadoun Square and is due to finish at the Bardo museum, where a stone tablet will be dedicated to the victims of the attack.
Thousands of police officers have been stationed around Tunis to guard the safety of people as they take part in "Le Monde est Bardo" (The World is Bardo) protest.