Tunisian police killed three Islamist militants in Sidi Bouzid, a security source told Reuters.
Police seized weapons in the operation, the source added, without giving details.
The Interior Ministry said security forces foiled attacks planned in the holy month of Ramadan after they arrested “a dangerous terrorist” last week.
One of the Arab world’s most secular nations, Tunisia became a target for militants after being hailed as a beacon of democratic change with an uprising against autocrat Zine Abidine Ben Ali in 2011.
Tunisia suffered three major attacks in 2015, including two against tourists, one at a museum in Tunis and the second on a beach in Sousse. The third targeted presidential guards in the capital. All three attacks were claimed by Islamic State.