It said the operation in the rugged mountainous Tounine area some 30 kilometres (20 miles) south of the coastal town of Gabes began after the authorities were alerted to the presence of a “terrorist group.”
Two militants were killed on Monday in an exchange of fire in which a member of the National Guard gendarmerie was also wounded.
On Tuesday morning, a specialized unit entered a cave where a third suspected terrorist had taken refuge. He was killed in another exchange of fire.
Later in the day a fourth man — “at first indications a foreigner” — was wounded and arrested, the ministry said.
Guns and ammunition were seized during the ongoing operation, it added.
There was no immediate information about the identities of those killed or what group they may have belonged to.
Extremist militants have killed dozens of police and soldiers since the 2011 revolution that ousted longtime dictator Zine El Abidine Ben Ali.
Last year alone, the ISIS group claimed attacks on the national museum in Tunis and a popular resort hotel, killing a total of 59 tourists, and the suicide bombing of a bus that killed 12 presidential guards.
The attacks further damaged the tourism-reliant economy of the North African nation, which has still to recover since the revolution five years ago, AFP reported.
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