Tunisian authorities on Tuesday recognised that two jihadist groups which the army has been hunting on the Algerian border have links to Al-Qaeda, stressing their determination to take them out.
"There are two groups, one in the Kef region with around 15 people and the other in Mount Chaambi with around 20 people," interior ministry spokesman Mohamed Ali Aroui told reporters, referring to the groups being pursued by the army since last week.
"There is a connection between the two groups, and the one in the Chaambi region has ties with the Okba Ibn Nafaa brigade, which is linked to Al-Qaeda."
"We will respond militarily to anyone who takes up arms against the state," Aroui added.
Since the revolution in January 2011 that ousted Zine El Abidine Ben Ali, Tunisia has seen a sharp rise in the activity of radical Islamist groups that were suppressed under the former dictator.
Those groups have been blamed for a wave of violence, notably an attack on the US embassy last September and the assassination of a leftist opposition leader in February, cases which the ruling Islamist party Ennahda has sought to portray as isolated incidents.
The army says there have been no direct clashes with the jihadists hiding out in the remote Mount Chaambi region, but homemade devices have so far wounded 16 members of the security forces involved in the hunt, five of whom lost legs.
Homemade explosives, coded documents, maps and mobile phones were discovered at a camp used by the group, and the army troops has been using mortar fire to try to demine the area.
Aroui said the Chaambi fighters were from "neighbouring countries," notably Algeria, while army sources on the ground have said some were veteran Islamist militants who fought in northern Mali.
"They wanted to make Chaambi their base, but we have dismantled it and they no longer have a refuge," said army spokesman Mokhtar Ben Nasr, adding that Tunisia and Algeria, which share a porous border often used by smugglers, were cooperating on the case.
The authorities have given no information on the operations in Kef, a region about 100 kilometres (60 miles) to the north, where the second jihadist group is based.
Tunisia's President Moncef Marzouki went to meet the troops involved in the search operations on Tuesday, according to his office.
"We are currently experiencing a crisis that requires a national effort," Marzouki's spokesman Adnene Manser told reporters.
"We need to have confidence in our army and give it strong support in combatting this threat," he said.
The opposition in Tunisia have strongly criticised the government for not managing to catch the jihadists, and have condemned the poorly-equipped state of the armed forces.
Ennahda in particular, long blamed for failing to rein in Tunisia's militant Islamists, has been accused of recognising the threat they pose too late, despite the security problems they have caused since the revolution.
In December, the authorities announced the arrest of 16 militants belonging to the Okba Ibn Nafaa brigade, described as a cell of Al-Qaeda in the Islamic Maghreb, in Tunisia's Kasserine region, where Mount Chaambi is located.
But they had not until now confirmed a link between those arrested and the "terrorist group" hiding out in the Chaambi region that the security forces have been tracking since a deadly attack on a border post in December.
Tunisia's government has warned of jihadist groups linked to Al-Qaeda in the Islamic Maghreb infiltrating the country's borders in recent months and trafficking weapons.