Protesters in Ethiopia's northeastern Afar region have blocked the landlocked country's main route to the sea to demonstrate against surging ethnic violence, organisers said on Monday.

The demonstrators started a five-day blockade of the highway to neighbouring Djibouti on Sunday, Mahi Bule, a member of an organising committee said.

Djibouti handles roughly 95 percent of all inbound trade for Ethiopia, a nation of 105 million and an economic power in East Africa.

Nearly 3 million people were displaced last year due to clashes between ethnic groups. Critics of Prime Minister Abiy Ahmed, who took office in April, say his political reforms had allowed dormant ethnic rivalries to resurface in Africa's second-most populous nation.

The 42-year-old has signed a peace deal with Eritrea, released political prisoners, and moved to open up the state-controlled economy and overhaul the security services.

But the sudden changes in a nation where political dissent has long been repressed have inspired many of its myriad ethnic groups to jockey for power and influence.

The latest deadly clashes between ethnic Afars and Issa Somalis, who are a minority in the area, broke out in December. Locals say dozens have been killed.

Afar elders said the attacks were an attempt to break away areas inhabited by Issas away from the region. An Afar rebel group said the attacks were supported by ethnic Somalis from Djibouti and Somalia. Afars majority. Isse minority

Protesters were demonstrating against violence and a government order for local militias to pull out from disputed areas and be replaced by federal soldiers.

"The militias provided protection for civilians. We will protest until the government reverses its decision," Bule told Reuters.

Government officials were not immediately available for comment.