PARIS - Recordings of the Air Algerie plane crashed two weeks ago in Mali were currently "unusable," Bureau of Investigation and Analysis for Civil Aviation Safety (BEA) said on Thursday.

2nd black box of Air Algerie jet found

"Analysis continues to try to find a means of extracting some information, but it is not possible to predict the outcome of this approach," it added.

In a communqiue posted on its website, the French authority responsible for safety investigations into accidents in civil aviation, in coordination with counterparts from Algeria, Mali, Spain and United States, pointed to the necessity "to collect all data on communications that the crew may have made with organizations on the ground or with other aircraft."

According to preliminary investigation, the Spanish MD-83 aircraft had climbed normally but "quickly lost altitude," after changing its route "typical of a strategy to avoid any stormy developments," the BEA said.

An interim report will be published in mid-September by the President of the Mali Commission of Inquiry, it added.

On July 24, an Air Algerie plane carried 118 passengers including 54 French nationals, was reported missing 50 minutes after it took off from Burkina Faso to Algiers.

The plane's debris was founded south of the northern Malian town of Gossi, near the Burkina Faso border.

French top official said bad weather could be the most likely cause of the air accident but no theory was excluded.