The former governing party in Ethiopia's Tigray region has said it was back in control of the regional capital Mekelle, and the government which ousted its leadership late last year declared a ceasefire with immediate effect.

Seven residents in downtown Mekelle reported seeing rebel troops in the city for the first time since they were driven out by government forces in November, and several witnesses described scenes of jubilation in the streets.

"The capital of Tigray, Mekelle, is under our control," Getachew Reda, spokesperson for the Tigray People's Liberation Front (TPLF), said by satellite phone.

Ethiopia's government said it had agreed to a ceasefire following a request from the interim regional administration in Tigray, which Addis Ababa appointed after ousting TPLF forces.

"This unilateral ceasefire declaration starts from today June 28, 2021 and will stay until the farming season ends," a statement released by the federal government late today read. Ethiopia's main planting season lasts from May to September.

Reuters could not immediately establish whether the ceasefire was discussed with the TPLF.

The Ethiopian prime minister's spokesperson and the military's spokesperson did not respond to phone calls and messages seeking comment. The TPLF could not immediately be reached for comment on the ceasefire.

UN Secretary-General Antonio Guterres said he had spoken with Prime Minister Abiy Ahmed and was "hopeful that an effective cessation of hostilities will take place".

"It is essential that civilians are protected, humanitarian aid reach the people in need and a political solution is found," Mr Guterres said in a statement.

Today's developments followed recent reports of an escalation in fighting between government troops and the TPLF outside Mekelle.

Last week, residents reported that TPLF forces had entered several towns north of Mekelle, although in at least one case they withdrew within hours.

Last Tuesday, an air strike killed over 60 people in the town of Togoga, to the northwest of Mekelle, a medical official told Reuters.

Colonel Getnet Adane, Ethiopia's military spokesman, said last week that only combatants, not civilians, had been hit.

The attack was one of the deadliest reported incidents in months in a region where the government had said most major fighting ended last year.