ADDIS ABABA, Ethiopia (AP) – A spokesman says Ethiopian Airlines has grounded all its Boeing 737 Max 8 aircraft as a safety precaution, following the crash of one of its planes in which 157 people were killed.

Asrat Begashaw said Monday that although it is not yet known what caused the crash on Sunday, the airline decided to ground its remaining four 737 Max 8 planes until further notice as “an extra safety precaution.” Ethiopian Airlines was using five new 737 Max 8 planes and was awaiting delivery of 25 more.

Begashaw said searching and digging to uncover body parts and aircraft debris will continue. He said forensic experts from Israel have arrived in Ethiopia to help with the investigation.