Authorities said the woman supported extremist religious ideas and as well as the kidnappings and was planning to attack military and security personnel using improvised explosive devices.
“The woman aimed to kidnap children of a number of policemen and soldiers to bargain for the release of [extremist] prisoners implicated in terrorist operations,” the ministry said on its official Facebook page.
It said she planned to carry out a suicide bombing using an explosive belt inside a security facility.
The woman had previously been jailed for terrorism-related convictions, the ministry said.
It did not name the woman or say when she was arrested.
“The operation was carried out jointly by the Anti-Terrorism Department of the National Guard and the Department of Prevention and Combating Terrorism of the Intelligence and Security Agency for National Defence and under the supervision of the Public Prosecution Office,” it said.
Saturday’s announcement comes as the North African country suffers a worsening political crisis after President Kais Saied seized executive power last year.
The case has raised questions about women's active and willing participation in violent extremism.
There is little data on the number of female extremist recruits across the region, but anti-terror experts say the role of women has evolved from assisting men and indoctrinating children to carrying out suicide bombings.
In April 2021, a woman detonated an explosive belt, killing herself and a baby, during a security operation against extremist groups in Kasserine province.
In October 2018, a woman blew herself up in the centre of Tunis, wounding 15 people, including 10 police officers. The attack shattered a period of calm that had held since dozens were killed in ISIS attacks on key tourist locations in the country in 2015.
Sousse was the scene of one of Tunisia's worst attacks in 2015, when 38 people, most of them British tourists, were killed by a gunman.
Several thousand Tunisians travelled overseas to join and fight for extremist groups in Libya, Syria, Iraq, Afghanistan and elsewhere between 2011 and 2016, International Crisis Group said in a report.
Since the international coalition destroyed ISIS in Iraq and Syria and Al Qaeda capabilities have degraded, the number of extremist attacks has dropped considerably in Tunisia, which has adopted strict counter-terror measures during the past nine years.