Turkey, which has a military base in the Gulf kingdom.

This is not the first time the two countries have fallen out.

Reason 1: Disputed borders
Aside from Eritrea, two other territorial disputes have strained Sudanese-Egyptian relations during the past half century.

The province of Darfur, in western Sudan, has been riddled by war for the past two decades, with up to 300,000 dead and at least 2.7 million displaced.

In May last year, President Omar al-Bashir said: “The Sudanese army has captured several Egyptian armoured vehicles in recent fighting in Darfur.” He has also previously accused Egyptian intelligence services of supporting opposition figures fighting his troops in the conflict zones of Blue Nile and South Kordofan.

Member of the Sudan Liberation Army (Abdul Wahid faction) in North Darfur in May 2012 (UNAMID)

However, EgyptianPresident Abdel Fattah al-Sisi dismissed the accusations and said Cairo was not playing a role in Darfur. Rebel leaders have also rejected Bashir’s comments.

Then there is the Halaib Triangle to the north of Sudan, run in effect by Egypt for the past two decades and which Cairo says is Egyptian territory. The region, rich in minerals and oil, has been disputed by Egypt and Sudan since the latter became independent in 1956.

Cairo has increased its military presence in the area since 1996, despite Khartoum’s repeated complaints to the UN Security Council and calls for the dispute to be solved through arbitration.

In January 2016, Sudan put its forces on standby on the border with Egypt, the first time it has done so in 60 years, saying that Egypt’s military