ADDIS ABABA, Ethiopia—An Ethiopian official says nine people were arrested last week on suspicions of organizing a terrorist network and planning attacks.

Government spokesman Shimeles Kemal said Wednesday that two journalists were among those arrested. He says they were involved in planning attacks on infrastructure, telecommunications and power lines. Shimeles says two other suspects are members of an opposition party.

Shimeles says the suspects were supported by Ethiopia’s archenemy Eritrea and by an international terrorist group, which he did not name.

International media rights groups have been calling for the release of Reeyot Alemu, a columnist for the independent weekly Feteh, and Woubshet Taye, deputy editor-in-chief of the weekly Awramba Times newspaper.