Explosions were heard overnight in Ethiopia's capital Addis Ababa, three diplomatic sources said on Thursday, adding to anxiety about the possible spread of renewed conflict in the country's north. 

A source linked to the opposition alliance fighting government forces in northern Ethiopia since last week said the alliance had carried out several drone strikes in Addis Ababa, including some targeting the military's headquarters.

Reuters could not independently verify the claim and there was no damage visible near the military base, witnesses said. 

The sources, who gave scant details of the blasts, spoke on condition of anonymity to discuss a sensitive matter. 

If confirmed, it would be the first known drone attack by anti-government forces on the Ethiopian capital, which is hundreds of kilometres from the front lines in the northern regions of Tigray, Amhara and Afar. 

Spokespeople for Prime Minister Abiy Ahmed's office, the federal government and the Ethiopian National Defence Force (ENDF) did not immediately respond to requests for comment. 

INTELLIGENCE SERVICE BANS DRONE FLIGHTS OVER CAPITAL

Last week's clashes were the biggest escalation in Ethiopia since the end of a 2020-2022 civil war.

The national intelligence service had announced on Wednesday that it was banning drones over Addis Ababa and its surroundings for security reasons. 

Opposition forces had not previously been known to use armed drones but there is growing evidence they may possess some capability.

On Tuesday, a pro-government militia said it had captured drone frames and batteries from forces linked to the Tigray People's Liberation Front (TPLF), one of the alliance's main members. 

Reuters could not independently verify that.

Edward Bach, Senior Africa Analyst at risk intelligence company Verisk Maplecroft, said the opposition's ability to strike Addis Ababa would be "a political game-changer," undermining any government narrative that the capital is unaffected by the war and narrowing a key tactical advantage for federal forces, their aerial superiority. 

TENS OF THOUSANDS DISPLACED BY FIGHTING

Last week's outbreak of fighting shattered a four-year-old peace deal between the TPLF and the federal government, whose previous two-year civil war killed hundreds of thousands.

This time, the TPLF has formed an alliance with six other armed groups aiming to overthrow Abiy's government. 

Federal forces have been advancing in southern Tigray, edging closer to the regional capital Mekelle, while the opposition alliance has captured towns in neighbouring Afar.

The pro-government Tigray Peace Forces militia said on Wednesday that it had captured the Tigrayan town of Korem, about 100 km south of Mekelle, alongside the Ethiopian military. 

In Afar, where the TPLF captured several towns in the early days of the new conflict, fighting has forced tens of thousands of people to flee their homes, Valerie Browning, a founder of the Afar Pastoralist Development Association, told Reuters. 

An Afari government official told Reuters on Thursday that federal and regional forces had recaptured the towns of Erebti and Abaala, near the border with Tigray.

Reuters could not independently confirm battlefield reports. 

FEARS OF REGIONAL DESTABILISATION 

The conflict could further destabilise the wider Horn of Africa region, already unsettled by Sudan's civil war, frictions over Red Sea access between Ethiopia and neighbouring Eritrea, and spillover from Middle East conflicts. 

Ethiopia's government has accused Eritrea, Sudan and Egypt of supporting the opposition alliance. All three deny that. 

Afar's chief administrator Haji Awol Arba went a step further earlier this week, telling Al Jazeera that Eritrean soldiers had crossed into Afar to join the alliance's offensive.

Eritrea's information minister did not immediately respond to a request for comment. 

In the previous civil war, Eritrea fought in support of Ethiopia's federal government against the TPLF. But relations between the two historical rivals soured after the war, with Asmara viewing Abiy's repeated assertions that landlocked Ethiopia has a right to sea access as an implicit threat. 

Abiy has said Ethiopia intends to secure sea access through peaceful means.