President Omar al-Bashir announced Sunday he severed relations with neighboring Chad, accusing the government of supporting rebels who attacked the Sudanese capital, according to state media.

The president, wearing his military uniform, appeared on state television and said he held Chad responsible for the Saturday night assault by Darfur rebels on Khartoum, the independent English language daily Sudan Tribune reported.

“Al-Bashir announces the severing of relations with Chad,” reads a headline on a brief news story from the official SUNA news agency. The news agency added that the president had just returned from Saudi Arabia where he was performing a pilgrimage.

Relations between the two countries, which share a long arid border region home to numerous armed groups, have long been strained.

On Saturday, Sudan’s interior minister accused Chad of supporting what he called “mercenaries,” who aimed to hit Khartoum. “Chad wants to hit Sudan in the heart,” Interior Minister Ibrahim Mahmoud Hamed told state TV.

Sudan also accused Chad of attacking a border area to provide cover for the Saturday night assault by rebels from Darfur’s Justice and Equality Movement. The government said the attack was repulsed and the rebels crashed.

Chad has accused Sudanese authorities of arming rebels who launched a failed assault in February on the Chadian capital, N’Djamena. The rebels reached the gate of the presidential palace, but fled toward Sudan after Chad’s army repelled them in fighting that left hundreds dead.

Sudan, meanwhile, has repeatedly accused Chad of supporting the rebellion in Darfur.

Though the two countries signed peace agreement in March promising to prevent armed groups from operating along each other’s shared borders, the accusations have continued unabated.