town of Ben Guerdane, Tunisia
A police officer picks up a rocket-propelled grenade (RPG) after an attack by Islamist fighters in the town of Ben Guerdane, TunisiaReuters

Tunisia's government says the death toll has risen to 53 in clashes between gunmen and security forces in Ben Guerdane, a town bordering Libya. The statement says 35 extremists, 7 civilians and 11 members of the security forces have been killed in fighting that began at dawn on Monday 7 March.

"I saw a large number of activists at dawn, who ran with their Kalashnikovs", a local resident told Reuters. "They said they were from the Islamic State and they came to attack the army and the police," he said.

Speaking from the capital Tunis, President Beji Caid Essebsi said extremists now pose a security threat to all of Tunisia. "This is an unprecedented attack, planned and organized. Its goal was probably to take control of this area and to announce a new emirate. The majority of Tunisians are now in a state of war against barbarism," Essebsi said on Monday.

Bodies were lying in the streets with gunmen still at large and hiding in homes in the Tunisian town of Ben Guerdane. The attackers targeted an army barracks and police posts with heavy weaponry, including rocket-propelled grenades. Gunfire still rang out as darkness fell on Monday night. Interior and defense ministries said that security operations are continuing in the town.

"If the army had not been ready, the terrorists would have been able to raise their flag over Ben Guerdan and gotten a symbolic victory," said Abd Elhamid Jelassi, vice president of the Islamist party Ennahda, part of the government coalition.

"I see three corpses on the ground," said resident Raoudha Bouttar, a local journalist. Another witness said the gunmen spoke of creating a caliphate and "liberating" the town.

Monday's clashes are amongst the deadliest violence Tunisia has seen between security forces and extremists. No group has officially claimed responsibility for the attack in the town of Ben Guerdane on Tunisia's eastern border. But commentators on two Islamic State-affiliated websites say militants loyal to the extremist group are involved in the attack, according to an AP report.

Ben Guerdane is a strategically important town that is regarded as the "gateway to Libya". It serves as a centre for arms trafficking and smuggling of contraband goods.