Investigation underway following Algeria's In Amenas attack

Militants disguised themselves to gain entry to the gas complex Algiers – Hocine Bousalah Algerian intelligence and security services have kickstarted an investigation into 11 workers from the In Amenas gas station suspected of collaborating with the terrorist group that stormed the complex on Wednesday, creating an international hostage crisis.
The workers include four security officers from BP, five from Sonatrach and two kitchen staff from Japanese company GGC.
Inquiries began on Friday as Algerian investigators collected phone numbers from BP, Sonatrach and Statoil, checking calls made by workers up to three months before the attack.
Authorities want to determine how the kidnappers, from the al-Qaeda-linked group the Signatories in Blood Brigade, managed to secure four vehicles similar to those used by armed security guards from Sonatrach.
Initial examinations proved the vehicles were not stolen and had been modified to match Sonatrach transport in order to deceive security at the complex’s main gate. It is believed the source of these new vehicles is Libya.
Interrogating workers revealed the militant group were well trained and were reportedly using drawings detailing the plant, suggesting the attack was planned long in advance and presumably received help from insiders.
Preliminary investigations also revealed allegedly suspicious phone calls with unknown individuals in Mali and Libya. One of these calls was made on January 10, reportedly by a man who later disappeared along with his family. Authorities are currently looking for the individual.
Security services apprehended three mobile phones after arresting five kidnappers on Sunday. They are currently examining contacts on the handsets.
Well-informed sources meanwhile told Arabstoday that the kidnappers were dressed in Libyan military uniforms during the attack.
Witnesses involved in the assault confirmed that the majority of armed men were wearing new Libyan uniforms, while another man, now named as Ahmed Abu Shanab, wore a dark green military uniform in line with those worn by oil station guards inside Libya.
Security forces have also revealed the name of one of the hijackers, a Tunisian man known as Abu Talha. He is believed to be the mastermind of the operation.
The same sources confirmed that Abu Talha oversaw the training of militants in Niger for two months, also requesting Mokhtar Belmokhtar’s help while in Mali.
Security experts meanwhile revealed to Arabs today that Belmokhtar had extensive relationships inside Libya, having supported the Libyan rebels during the 2011 rebellion against the Gaddafi regime.