Ethiopia’s government declared an immediate, unilateral ceasefire on Monday in its Tigray region after nearly eight months of deadly conflict.

The cease-fire could calm a war that has destabilized Africa’s second most populous country and threatened to do the same in the wider Horn of Africa, where Ethiopia has been seen as a key security ally for the West.

It comes as the country awaits the results of national elections that Prime Minister Abiy Ahmed promoted as the centerpiece of reforms that won him the 2019 Nobel Peace Prize.

Abiy’s transformation from making peace to waging war has appalled many observers since the fighting in Tigray erupted in November.

Since then, the world has struggled to access much of the region and investigate growing allegations of atrocities including gang rapes and forced starvation. Thousands of people in the region of 6 million have been killed.

Ethiopia’s statement was carried by state media shortly after the Tigray interim administration, appointed by the federal government, fled the regional capital, Mekele, and called for a cease-fire on humanitarian grounds so that desperately needed aid can be delivered.

UN Secretary-General Antonio Guterres said in a statement that he had spoken with the prime minister and “I am hopeful that an effective cessation of hostilities will take place.”

Meanwhile, Mekele residents cheered the return of Tigray forces for the first time since Ethiopian troops took the city in late November and Abiy declared victory.

The Tigray fighters, loyal to the former regional ruling party that for years dominated Ethiopia’s government before being sidelined by the new prime minister, undermined the declaration by waging a guerrilla war in the region’s rough terrain.

As Tigray forces occupied the airport and other key positions in Mekele and broadcast a message telling residents to stop celebrating and go home, retreating Ethiopian soldiers shot at students at Mekele University, killing two and wounding three, said a nurse at Ayder hospital, who spoke on condition of anonymity out of fear of retaliation.

Monday’s cease-fire declaration signaled a new approach, at least for a while.

The cease-fire “will enable farmers to till their land, aid groups to operate without any military movement around and engage with remnants (of Tigray’s former ruling party) who seek peace,” Ethiopia’s statement said, adding that efforts to bring Tigray’s former leaders “to justice” continue.

Ethiopia said the cease-fire will last until the end of the crucial planting season in Tigray which ends in September.

Amid the upheaval on Monday, the United Nations children’s agency said Ethiopian soldiers entered its office in Mekele and dismantled satellite communications equipment, an act it said violated the world body’s immunity. UNICEF last week warned that at least 33,000 severely malnourished children face “imminent risk of death” without more aid reaching Tigray’s people.

At UN headquarters in New York, the US, UK and Ireland called for an emergency open meeting of the Security Council. The UN’s most powerful body has discussed Tigray behind closed doors but not in an open session. They need support from nine of the 15 council members to hold an open meeting.