Four security officers and two suspected fighters have been killed in two separate incidents in the south of Tunisia and near the capital Tunis, according to government sources.
A fighter detonated his explosives belt after a firefight erupted in the Tatouine governorate on Wednesday, killing the officers.
"One terrorist element was shot dead while the other detonated his explosives belt, killing two officers and two agents of the national guard," said the interior ministry.
Tunisia, the birthplace of the 2011 Arab uprisings, has suffered from a wave of violence since its revolution that toppled Zine El Abidine Ben Ali, the longtime president.
Earlier on Wednesday, two suspected fighters were killed during the raid in Ariana province, just outside Tunis, against a cell planning "simultaneous" attacks, according to AFP news agency.
A national guard unit had carried out the raid acting on information from an "anti-terrorist" operation.
Sixteen others were arrested during the operation in Ariana and AK-47 rifles, pistols and ammunition were seized.
The interior ministry said the suspects had gathered in the area from different parts of the North African nation.
According to a resident of the Sanhaji district, a two-hour gun battle erupted with the suspects after the National Guard launched the raid at around 8am local time (07:00 GMT).
|Tunisia, the birthplace of the Arab uprisings, has suffered from a wave of violence since 2011 [Reuters]
"They were not from the neighbourhood. We didn't know them. They rented the house recently," AFP quoted her as saying.
The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group claimed responsibility for attacks last year on the National Bardo Museum in Tunis and a beach resort near Sousse that killed a total of 60 people, all but one of them foreign tourists.
A suicide bombing in Tunis in November, also claimed by ISIL, killed 12 presidential guards and prompted the authorities to declare a state of emergency.
Strike in border town
In another development, a southern town in Tunisia a staged a general strike on Wednesday in protest against a decision by Libyan authorities to halt cross-border trade on which its economy depends.
Ben Gardane, one of the country's poorest towns, was the target of an assault from across the border in Libya that killed seven civilians and 13 security personnel in March as well as 55 fighters.
Shops and offices in the town of 60,000 inhabitants were all closed in response to the one-day strike called by the UGTT main trade union confederation, an AFP correspondent reported.
Only the hospital emergency department, a pharmacy and some schools remained open in the town, whose economy is heavily dependent on cross-border trade and where smuggling is rife.
Libyan border officials say they had halted all freight traffic since the end of April through the Ras Jedir crossing in a bid to stop the smuggling of fuel, which is much cheaper across the border.
Negotiations focused on customs duties have so far failed to reach a settlement.
Fayez al-Sarraj, Libya's prime minister-designate, met on Wednesday in Tunis with President Beji Caid Essebsi.
"The anti-terrorist struggle was at the top of the subjects raised, as well as our aim of an economic partnership," Sarraj said.
For its part, the Tunisian presidency said the situation at Ras Jedir was discussed in the meeting.