Ethiopia’s prime minister has called on his supporters to redouble their efforts in the country’s war, as rival Tigray forces claimed to have seized key cities that control a major road heading towards the capital.

A move on the capital, Addis Ababa, would signal a new phase in the war that has killed thousands of people since fighting broke out almost a year ago between Ethiopian government troops and Tigray forces in the country’s northern region.

The prime minister’s spokeswoman, Billene Seyoum, did not immediately respond to a question on Monday about the government leader’s current whereabouts or travel plans.

Prime minister Abiy Ahmed said federal troops are fighting on four fronts against the Tigray forces and that “we should know that our enemy’s main strength is our weakness and unpreparedness”.

The Tigray forces have told The Associated Press they are poised to physically link up with another armed group, the Oromo Liberation Army, after they struck an alliance earlier this year.

The Tigray forces now claim to control the key cities of Dessie and Kombolcha, though the federal government disputes this claim.

The fighting could reach the Oromo region that neighbours the country’s capital.

Ethnic Oromo once hailed Mr Abiy as the country’s first Oromo prime minister, but discontent has since emerged with the jailing of outspoken ethnic leaders.

Also on Sunday, the government of the Amhara region, where fighting has been focused since Tigray forces retook much of their own region in June, ordered almost all government institutions to stop their regular activities and join the war effort.

It also banned most activities in cities and towns after 8pm.

The Tigray forces say they are pressuring Ethiopia’s government to lift a months-long blockade on their region of around six million people.

Tigray leaders had long dominated the national government before Ahmed took office in 2018.