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 jihadists hiding out in the remote Mount Chaambi region are blamed for an attack on a border post in December that killed a member of the national guard.

The army says there have been no direct clashes with the group, but homemade explosive devices they have place in the area have so far wounded 16 members of the security forces involved in the hunt, five of who lost legs.

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 a search for the second group was launched on Tuesday in Kef, some 100 kilometres (60 miles) to the north.

"An extensive search is underway in the Kef and Jendouba mountains," also close to the Algerian border, Ben Nasr said, without elaborating.

Tunisia and Algeria share a long, porous border which is often used by smugglers, and the army spokesman said the two countries were cooperating in the hunt for the jihadists.

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 combating this threat," he said.

Tunisia's opposition has strongly criticised the government for failing to catch the jihadists, accusing it of recognising the threat they pose too late, despite the problems they have caused, and condemning the poorly-equipped state of the armed forces.

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 (AQIM ), 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" holed up in the Chaambi region that the security forces have been tracking since the deadly December attack on the border post.

The government has in recent months warned of jihadists linked to AQIM infiltrating Tunisia's borders and undermining its stability, especially since their occupation of northern Mali last year.

Bolstering those concerns, a leader of Al-Qaeda's north Africa affiliate urged Muslims worldwide to attack French interests in retaliation for France's military intervention in Mali, in a video recorded last month and posted online. There are an estimated 30,000 French citizens living in Tunisia.