Ethiopia's government has declared three days of mourning after confirming that many Ethiopians held captive in Libya were killed by the Islamic State group.
The group released a video of the killings on Sunday.
The government said the days of mourning will start on Tuesday and the national flag will fly at half-mast during this time.
A statement said the country's politicians will meet to discuss the killings and consider a response.
A 29-minute video believed to be released by the Islamic militants shows Ethiopian Christians held captive in Libya being shot or beheaded by extremists.
Redwan Hussein, an Ethiopian government spokesman, said he believed the victims were Ethiopian migrants trying to reach Europe.