Interior Minister Najim Gharsalli says security forces have “broken the spine” of group behind museum attack in March.
Tunisian forces have killed one suspected fighter and arrested at least 16 others in a series of raids, as lawmakers debated need for tougher anti-terrorism laws following a spate of deadly attacks.
The series of overnight raids, which continued into the early hours of Friday started in Sejnane, in the northern Bizerte region, “against terrorists preparing terrorist acts,” said the interior ministry.
In that raid the first 13 suspects were arrested, and one person was killed.
Another raid was launched on Friday at dawn in the town of Menzel Bourguiba, resulting in three further arrests.
The ministry said weapons including explosives, ammunition and several assault rifles were seized during the operations.
Al Jazeera’s Hashem Ahelbarra, reporting from the capital, Tunis, said authorities received reports that gunmen were trying to launch an attack, prompting the government to move in.
The operation continues in the area as of 13:00 GMT, our correspondent said.
Tunisia has faced a spate of attacks this year, including a massacre at a Tunis museum in March that killed 22 people, mostly tourists, and a mass killing at a beach resort last month that left 38 foreigners dead.
The attacks, both claimed by the Islamic State of Iraq and the Levant (ISIL) group, have taken a toll on Tunisia’s vital tourism sector.
Authorities have pledged to crack down on extremism and lawmakers have this week debated a bill aimed at beefing up powers to confront the threat from ISIL.
On Thursday, the parliament approved imposing the death penalty for those convicted of “terrorist” crimes.
Lawmakers voted heavily in favour of three articles imposing the death penalty.
The security bill would replace the 2003 terrorism law, passed under the dictatorship of president Zine El Abidine Ben Ali, ousted four years ago, which was widely criticised as being a tool to crush dissent.
President Beji Caid Essebsi imposed a state of emergency after the latest shooting rampage in the country.
The death penalty already exists under Tunisian law, for such crimes as murder and rape, but no one has been hanged since 1991.
Rights groups had hoped parliament would leave it out of the current bill.
Advocacy groups, including Amnesty International and Human Rights Watch, have condemned the bill.
Describing it as draconian, they said its definition of terrorist crimes is too vague and that it fails to adequately safeguard the rights of defendants and could undermine freedoms.
Al Jazeera’s Ahelbarra said that parliament is expected to vote on the final bill either on Friday or Saturday. He said that rights groups have raised alarms that the new bill would “undermine newly-found freedom” in the country.