ISTANBUL (AP) — The technical analysis of the black boxes retrieved from the plane crash that resulted in the deaths of eight people, including the Western Libyan military chief, has begun as part of an investigation being conducted in collaboration with the Libyan authorities, Turkey's Defense Ministry said Thursday.

The private jet, which was carrying Gen. Mohammed Ali Ahmad al-Haddad, four other senior military officials, and three crew members, crashed shortly after taking off from the Turkish capital Ankara on Tuesday, killing all those on board. Libyan officials said the cause of the plane crash was a technical failure of the aircraft.

A high-level Libyan delegation, which had been in Ankara for defense talks aimed at strengthening military cooperation between the two countries, was on its way back to Tripoli.

Debris was scattered over an area of more than 3 square kilometers (1.2 square miles), complicating rescue efforts, Interior Minister Ali Yerlikaya said.

A 22-member delegation, including five family members, arrived from Libya on Wednesday morning to help with the investigation.