Celebrating their dramatic diplomatic thaw, the leaders of Ethiopia and Eritrea on Tuesday officially opened the border where a bloody war and ensuing tensions had divided them for decades, with emotional residents embracing after years of separation.

Abiy Ahmed, Ethiopia's new reformist prime minister, and Isaias Afwerki, the longtime president of Eritrea, visited the Bure Front along with members of their militaries to mark the Ethiopian new year, Mr Abiy's chief of staff Fitsum Arega said in a Twitter post.

The two opened the border post "for road transport connectivity" and later were doing the same at the Serha-Zalambesa crossing, Eritrean Information Minister Yemane Meskel said on Twitter.

Photos posted by both officials showed Mr Abiy in camouflage walking alongside Mr Isaias in olive drab, while hundreds of civilians lined a road with the countries' flags in hand.

Television footage showed people of the countries' Tigray region, who share close cultural ties, dancing while flag-draped camels wandered by.

The former bitter rivals have made a stunning reconciliation since Mr Abiy weeks after taking office in April announced that Ethiopia would fully embrace a peace deal that ended a 1998-2000 border war that killed tens of thousands.