By John Irish and Marine Pennetier
PARIS (Reuters) - France's foreign minister travels to Tunisia on Thursday aiming to firm up security and economic ties as Tunis struggles with rising Islamist militancy fueled by Islamic State's growth in neighboring Libya.
With its new constitution, free elections and secular history, France's former North African colony has been a target for jihadists looking to upset the young democracy just five years after the overthrow of autocrat Zine El-Abidine Ben Ali.
"Tunisia is an important symbol because there are few countries in the region to be reasonably optimistic about," said a senior French diplomat before the two-day visit by Foreign Minister Jean-Marc Ayrault.
"The attacks in Ben Guerdan show more than ever why we need to support the Tunisians."
About 50 militants stormed through Ben Guerdan on the Libyan border on March 9, assaulting army and police posts. That attack reinforced fears that violence is spilling over from Libya, where Islamic State has expanded amid widespread turmoil as two rival governments battle for control.
The clash came after three major militant attacks in 2015, including on at the famous Bardo Museum in Tunis, which officials say were carried out by militants trained in Libya.
France, a major economic partner, has at times come under fire from Tunisians since 2011 for appearing indifferent throughout the transition process.
But it has increasingly supported the country, fearing the growing chaos could derail its political transition.
More than 3,000 Tunisians have left to fight for Islamic State and other jihadist groups in Syria and Iraq. Security officials say Tunisians are taking more and more command positions in Islamic State in Libya.
"There is a general concern about the impact of the Libyan crisis on Tunisia. Attack after attack, we see the link with Libya, where we see Tunisians in Libya turning against Tunisia. Access is too easy," said a second French official.
In terms of security, Paris is providing intelligence for Tunisia's special forces and implementing a 20 million-euro package aimed at equipping them.
Several dozen French military advisers are also on the ground training them and studying how to boost the number of special forces. However, unlike Britain, Paris is not planning to send advisers to help Tunisians stop border infiltration.
Key to France's support is a 1 billion euro ($1.1 billion) aid package over 5 years to help Tunisia develop poor regions, stimulate job creation - especially for the youth - and modernize Tunisia's administration, a major hurdle to the disbursement of international aid.
"There is a socio-economic breeding ground on which radicalization is prospering," said the diplomat.
"There is a direct link between massive youth unemployment, neglected regions and the fact that Tunisia provides one of the largest contingents of foreign fighters for jihadists."
(Editing by Tom Heneghan)