At least seven police officers have been killed in Tunisia in clashes with Islamist terrorists, the BBC reported on Wednesday.
Heavy gunfire was reported in the central region of Sidi Bouzid, with at least two terrorists reported killed.
The violence came as thousands of anti-government protesters marched through the capital, Tunis, calling for the Islamist-led government to step down.
The protests come ahead of a national dialogue between the governing party, Ennahda, and the opposition.
Parliament speaker Mustapha Ben Jaafar said he expected Prime Minister Ali Larayedh to announce his intention to stand down.
Exactly two years ago, Tunisians elected the moderate Islamist Ennahda party in the country's first free and competitive elections. It formed a government in alliance with two secular parties.
The vote followed the overthrow of long-ruling strongman Zine El Abidine Ben Ali in the first revolt of the Arab Spring.
Since then, the country has been unstable, as Tunisians have accused Ennahda of turning a blind eye to the activities of more radical Islamist groups.
Last month, Ennahda agreed in principle to relinquish power, in an effort to end Tunisia's political deadlock.
The crisis was triggered by the assassinations of two secular opposition leaders earlier this year.
Since the 2011 revolt, Tunisia has seen a rise in attacks by terrorists.
In the latest attack, members of the National Guard surrounded a building in the village of Sidi Ali Bououn, following a tip-off that a suspicious group was hiding there, an interior ministry spokesman said, according to BBC.
A fierce gun battle ensued during which both security forces and terrorists were killed.
It comes just days after Tunisian security forces killed at least nine suspected Islamist terrorists who the authorities said had carried out a deadly attack on a police patrol.
The interior ministry blamed militants belonging to the Salafist Ansar al-Sharia group, who were linked to the murders of prominent left-wing figure Chokri Belaid in February and opposition politician Mohammed Brahmi in July.
Several other terrorist groups - including Al-Qaeda in the Islamic Maghreb - also operate in the region.