. >> reporter: islamic militant leader mokhtar belmokhtar has claimed responsibility for the attack. the u.s. federal bureau of investigation has filed charges against him as the alleged mastermind but his whereabouts remain unknown. an intelligence expert professor mathieu guidere says the threat remains. >> after the attack of amenas, mokhtar belmokhtar has appeared as the main leader, the chris mat tick leader in the region. >> reporter: he says algeria's intelligence agency is having problems cooperating with its counterparts in libya and tunisia where the security situations are not stable. >> what happened in amenas can happen again in other areas, not in amenas itself but in other locations. >> reporter: last year an association of engineering firms surveyed leading japanese companies doing business abroad and what they do to ensure the safety of their workers. 78% said they want japanese embassies to appeal on their behalf to local military and police forces. >> translator: there are limits to what private firms can do in terms of negotiating with foreign governments. >> repo