Four Tunisian police officers were killed during a "terrorist" attack overnight on the home of Interior Minister Lotfi Ben Jeddou in the west-central Kasserine region, a ministerial spokesman said Wednesday.
It was not immediately clear who, if anyone, was in the house at the time of the attack, but the minister himself normally stays in the capital Tunis while his wife and children live in Kasserine.
"Four police officers were killed and another injured during a terrorist attack with Kalashnikov rifles that targeted the Kasserine home of the interior minister," spokesman Mohamed Ali Aroui told AFP.
After the attack, traces of blood could be seen on the exterior walls of the house and on the ground near the building.
The assailants were hooded and arrived in a pick-up truck, a local resident told AFP.
Kasserine is situated at the foot of Mount Chaambi on a range bordering Algeria.
Since late 2012, security forces have been battling dozens of militants hiding out in the remote Mount Chaambi region, where eight soldiers were killed in an ambush last July.
Authorities say the militants are linked to Al-Qaeda. But jihadists have not claimed the attacks that have rocked Tunisia since the 2011 "Arab Spring" revolution, including two foiled suicide bombings last October targeting tourist sites.
The attack on the interior minister's house comes during a period of relative calm in Tunisia, after a bloody 2013, with the authorities talking of an improved security situation in recent months while warning that the anti-terror struggle will be a long one.
Last year, more than 20 security personnel were killed in what the government says were "terrorism-related incidents".
Two opposition politicians were also assassinated in separate attacks that plunged the country into crisis.
Last month, Tunis designated Mount Chaambi and neighbouring mountain districts a closed military zone, and warned of the growing threat posed by "terrorist organisations" based there.
Prime Minister Mehdi Jomaa insisted Sunday that the authorities were capable of "undermining the plans" of armed groups, but warned that battling jihadists would lead to as "heavy human losses as anywhere else in the world".
Tunisia has also been wary of the growing influence of Islamists in neighbouring Libya, and fears that lawlessness there could spill across the border.