Rebel forces from Ethiopia's Tigray region fired rockets into the city of Bahir Dar in the neighbouring Amhara region on Friday but caused no casualties or damage, the Amhara government said, as federal forces moved towards the Tigray capital.

‘The illegal TPLF group have launched a rocket attack around 1:40 a.m. in Bahir Dar,’ Amhara regional government's communications office said on its Facebook page.

‘The rockets have caused no damage.’

The conflict in northern Ethiopia has killed hundreds over the past two weeks, sent 33,000 refugees into Sudan, and called into question whether Prime Minister Abiy Ahmed - Africa's youngest leader and last year's Nobel Peace Prize winner - can hold his ethnically divided nation together ahead of national elections next year.

The northern-based Tigray People's Liberation Front (TPLF) effectively ruled Ethiopia for decades as the strongest force in a multi-ethnic coalition, until Abiy took power two years ago following years of bloody protests against government repression.

He released thousands of political prisoners, lifted bans on many political parties and put many officials from the old regime on trial for crimes like murder or corruption. The Tigrayans accused him of purging them from positions of power, accusations his government denies.

Amhara, which has a long-running border dispute with Tigray, has sent regional forces in support of the federal troops.

There have also been reports of ethnically motivated killings. International rights group Amnesty International documented a mass killing of civilians by what it says were Tigrayan forces on Nov. 9-10, and refugees fleeing the conflict into Sudan have said they were targeted because they were Tigrayan.

Tigray forces accused the government of bombing a university in the Tigray capital of Mekelle on Thursday. There was no immediate response from the government although officials have said they are only attacking military targets.

It has been impossible to verify assertions on all sides because telephone lines and internet connections to Tigray have been down since the beginning of the conflict.

Ethiopia said on Thursday it was closing in on Mekelle. The rebels have said they are fighting to defend it.

Africa's second most populous nation of 115 million people, Ethiopia is a federation of 10 states run by separate ethnic groups, many of whom have used the new freedoms that came under Abiy to jostle with the federal government and each other for more power, money or land.

Of those, mountainous Tigray - which accounts for about 5% of the population - is smaller but has a long history of dominating the security services.

Tigrayans are also proud of their long history of guerrilla warfare; they spearheaded a conflict that toppled a Communist regime in 1991.