Thousands of people have crossed the border that was closed for two decades.
Spokesperson Liya Kassa with Ethiopia's northern Tigray region tells The Associated Press it is not clear why Eritrea closed the crossings to Ethiopians. She says Eritreans are still crossing freely.
Liya says the Zalambessa and Rama crossings were closed as of Wednesday and preliminary information "indicates it was closed from the Eritrean side."
She says Eritrean border officials are now asking Ethiopian travelers to provide a travel document issued by federal authorities.
One Ethiopian traveler confirms the situation and says hundreds of people are affected.
Eritrean officials are not immediately available for comment