City authorities of Ethiopia's capital Addis Ababa on Tuesday called on residents to register weapons in the next two days after rebellious forces from the northern region of Tigray said they were considering marching there, state media reported.
People trying to create havoc were being arrested, a statement also said, without giving further details.
Federal government spokesperson Legesse Tulu did not immediately respond to a request for comment.
The call comes after a Tigray People's Liberation Front (TPLF) spokesman said Tigrayan forces took control of two cities - Dessie and Kombulcha - in the neighbouring region of Amhara, putting them about 380 km (235 miles) north of the capital.
On Monday night, Tigrayan forces said they had linked up with fighters from an Oromo force also fighting the central government and said they were considering marching on the capital.
The Oromo are Ethiopia's biggest ethnic group. Many of their political leaders are currently in prison.
The Tigrayan forces have been fighting the government for the past year in a widening war that first pitted federal troops against the TPLF, which dominated Ethiopian politics for nearly 30 years before Abiy Ahmed was appointed prime minister in 2018. The conflict has plunged around 400,000 people in Tigray into famine, killed thousands of civilians and forced more than 2.5 million people in northern Ethiopia to flee their homes.
