A landmine blast killed four Tunisian soldiers on Wednesday during a counter-terrorism operation in mountainous central Tunisia, the defence ministry said.

"Four soldiers who were part of a military unit tasked with carrying out a combing operation of Mount Mghila looking for terrorist elements were killed by a mine," ministry spokesman Mohamed Zekri told AFP.

Mount Mghila, near the border with Algeria, is adjacent to Mount Chaambi, which is considered a hideout for jihadists.

The sweep was "part of the regular anti-terrorist operations carried out by military forces in the region," Zekri said.

He said an operation was ongoing but declined to provide further details.

Tunisia has seen a surge in radical Islam since veteran president Zine El Abidine Ben Ali was ousted in the country's 2011 revolution.

Dozens of members of the security forces have been killed since then in jihadist attacks.

The security situation has greatly improved in recent years, but Tunisian forces continue to be targeted.

Tunisian Prime Minister Hichem Mechichi said Wednesday's incident "will not stop us from pursuing our efforts to fight and defeat terrorism".

"Our compass must always stay pointed towards protecting the nation from all dangers... far from all tensions and quarrels," he said in a statement, alluding to Tunisia's prevailing political climate.

Parliament approved a cabinet reshuffle a week ago but the new ministers are still waiting to be sworn in due to a standoff between President Kais Saied and key parties in the legislature.

Tunisia's bloodiest single attack against the army was in July 2014, when 15 soldiers were killed on Mount Chaambi.

The army has been battling militants in the rugged area since 2012.

Tunisia's mountainous central Kasserine region is also a hideout for the Tunisian branch of jihadist group Al-Qaeda in the Islamic Maghreb (AQIM) known as Okba Ibn Nafaa.

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