An armed group clashed with Tunisian security forces after attacking their post on the border with Algeria, leaving one of the assailants dead, the interior ministry said on Saturday.

An 18-year-old man was killed and a customs agent was wounded in the attack that took place at the Bouchebka post overnight, said ministry spokesman Mohamed Ali Aroui.

Algeria Friday defended its controversial military intervention to end the bloody seizure by armed Islamists last year of the In Amenas desert gas plant, in which 38 hostages were killed.

"The intervention by the Algerian security forces was imperative for saving hundreds of human lives and for protecting a strategic site that the terrorists were planning to blow up," foreign ministry spokesman Amar Belani said in a statement.

The elusive jihadist who staged a deadly siege of an Algerian gas plant a year ago, Moktar Belmokhtar, has the means to stage a similar attack, a top U.S. general said Thursday.

Belmokhtar was the mastermind behind an assault on a remote gas facility near In Amenas on January 16 last year that left 38 hostages dead, following a three-day siege and rescue attempt.

Libya and Algeria agreed Sunday to boost cooperation on border security, illegal immigration, weapons trafficking and "terrorism,” during a visit by Algerian Prime Minister Abdelmalek Sellal.

His trip to Tripoli, which follows a January summit in Ghadames between Algeria, Libya and Tunisia, was marred by protests demanding Libyan Prime Minister Ali Zeidan's resignation.

France's interior minister said Monday that a controversy over a joke made by French President Francois Hollande suggesting that Algeria was unsafe, which sparked a diplomatic row with Algiers, "was behind us".

The controversy erupted after Hollande joked during a speech last week to the CRIF Jewish representative group that French Interior Minister Manuel Valls had just returned "safe and sound" from a trip to Algeria, and "that's already a lot."

French President Francois Hollande on Sunday expressed his "sincere regrets" over a joke he made suggesting Algeria was unsafe, drawing a line under a brief but fiery diplomatic spat with the north African country.

Algerian Foreign Minister Ramtane Lamamra initially called the quip "regrettable" and said it ended the year on a "bad note", but later declared himself satisfied with Hollande's apology.

The United States on Wednesday blacklisted a shadowy al-Qaida breakaway faction behind the bloody siege of an Algerian gas plant.

The Signatories in Blood, an armed unit founded by the one-eyed Mokhtar Belmokhtar last year when he split from Al-Qaida in the Islamic Maghreb, was designated a foreign terrorist organization by the U.S. State Department.

Ailing President Abdelaziz Bouteflika is "well-informed" of developments in Algeria, despite having been largely unseen for months because of health woes, French premier Jean-Marc Ayrault said Tuesday after meeting him.

The 76-year-old president, in power since 1999, returned home in July after nearly three months in France recovering from a mini-stroke.

With chaos in Libya, military takeover in Egypt and Syria's brutal conflict threatening to extinguish hopes fueled by the Arab Spring, only Tunisia stands out even as its stability hangs in the balance.

By the end of 2013, the political forces that emerged from the tumultuous changes in the region nearly three years ago have yet to build the new democratic order or bring about the social transformations demanded by the millions who took to the streets.

A Moroccan protester who broke into the compound of Algeria's consulate in Casablanca and tore down the country's flag during a diplomatic row was given a two-month suspended sentence Thursday.

The November 1 incident came during a demonstration against comments by Algeria's President Abdelaziz Bouteflika over the disputed Western Sahara, and a video of it was widely circulated on Moroccan websites.