Ethiopian Airlines (EA) has suspended flights to and from Asmara, the capital of neighbouring Eritrea, citing “difficult operating conditions" beyond its control.

The move had been anticipated after the Eritrean government announced in July that the airline would no longer be allowed to operate in the country by the end of this month.

The state-owned airline, Africa’s largest air operator, had been speaking to the authorities in Asmara to try and address the complaints.

Flights only resumed between the two countries six years ago, after a 20-year break, in a highly symbolic move that represented the easing of historic tensions.

EA, which is the only airline to operate on the route, said that it would rebook affected passengers on other airlines - likely to be a more circuitous journey - at no additional cost.

In its July statement, the Eritrean Civil Aviation Authority accused EA of “malicious trading practices” and included a long list of grievances.

The Eritrean authorities said they had made “relentless calls” to EA to resolve the issues but said these efforts “bore no fruit”.

EA acknowledged receiving the suspension notice at the time but said that the specific reasons for the suspension had not been disclosed.

Many of those taking one of the two daily flights from Asmara to the Ethiopian capital, Addis Ababa, travel on from there to the rest of Africa, Europe and North America.

Several travellers in Eritrea told the BBC that they were surprised by the sudden suspension and were worried about the growing tension between the two countries.

There were celebrations when the airlink was re-instated in 2018.

Two decades earlier Ethiopia and Eritrea had fought a vicious border war in which tens of thousands had died.

Relations thawed after Abiy Ahmed became Ethiopia’s prime minister in 2018 and signed a “declaration of peace and friendship” with Eritrea.

The declaration won him the Nobel Peace Prize the following year.

But ties between the Horn of Africa neighbours have again deteriorated following the end of the two-year civil war in Ethiopia’s northern Tigray region, which borders Eritrea.

Asmara had been an ally of the Ethiopian government but has been lukewarm about the accord that ended the conflict in November 2022.

Relations were further aggravated by Mr Abiy’s pronouncement last year that his country wanted to secure access to a port on the Red Sea.

This raised concerns among neighbouring countries with coastlines, particularly Eritrea, whose secession in 1991 rendered Ethiopia landlocked.

With the land border closed, and the airlink between the two countries now suspended, telecom services are the only open connection between the neighbours.

Additional reporting by BBC Monitoring.