With communications to the province cut it was impossible to verify whether the military operation against the regional capital of Mekele had begun. Government forces said they had surrounded the city of 500,000 from 30 miles away.

“The Ethiopian National Defense forces have now been directed to conclude the third and final phase of our rule of law operation,” said the statement from the prime minister’s office. “We call on the people of Mekele and its environs to disarm, stay at home and stay away from military targets, and take all necessary precautions.”

The government campaign is against the political party controlling the province, the Tigrayan People’s Liberation Front, which once dominated the coalition that ruled the country for nearly 30 years. With the rise of Abiy, they retreated to their power base in Tigray and in recent months relations with the central government have declined dramatically.

The Ethiopian government has insisted its quarrel is only with the TPLF and not against the Tigrayan people and said the grace period was for the local forces to surrender.

“The last peaceful gate which had remained open for the TPLF clique to walk through has now been firmly closed as a result of TPLF’s contempt for the people of Ethiopia,” the statement added.

In messages to media outlets, the TPLF leadership has insisted that government forces have suffered several defeats. The Ethiopian government has countered by reporting surrenders among TPLF forces.

There has been widespread international concern about the campaign and calls for mediation that have been rejected by Abiy, last year’s Nobel Peace Prize winner, who has said the operation is an internal matter.

Aid workers said they had been unable to reach people who had been forced from their homes for weeks.

The prime minister’s office said in a Thursday statement that it would provide essentials to displaced citizens and clear the way for humanitarian groups, adding that the government “stands to support all Ethiopians that have fled to return to their communities.”

The pledge appeared to open a new path for desperately needed assistance, said Nigel Tricks, regional director of the Norwegian Refugee Council in Nairobi.

“People have gone from having a roof over their head,” he said, “to absolutely nothing.”