At least seven police have been killed in Tunisia in clashes with Islamist militants, reports say.
A heavy exchange of gunfire was reported in the central region of Sidi Bouzid and at least two militants were also reported killed.
The violence came as the Islamist-led government and opposition began talks to end months of political crisis.
Thousands of anti-government protesters marched through the capital, Tunis, calling on the prime minster to resign.
Parliament speaker Mustapha Ben Jaafar said he expected PM Ali Larayedh to announce his intention to stand down.
A coalition led by the moderate Islamist Ennahda party was elected in 2011. But some government critics have accused it of being soft on hardline Islamist forces - charges it strongly denies.
Since the popular revolt that sparked the "Arab Spring" in 2011, Tunisia has seen a rise in attacks by militants.
Militant groups
The latest violence comes just days after Tunisian security forces killed at least nine suspected Islamist militants who the authorities said had carried out a deadly attack on a police patrol.
At least three other suspects were arrested in the operation in the Mount Taouyer area, about 70km (44 miles) west of the capital, Tunis.
The interior ministry blamed militants belonging to the Salafist Ansar al-Sharia group, who were also linked to the murders of two secular opposition politicians earlier this year.
Their deaths triggered mass protests against Tunisia's Islamist-led government.
Several other militant groups - including al-Qaeda in the Islamic Maghreb - also operate in the region.
Source: BBC
