Chad has closed its eastern border with Sudan after clashes in recent days linked to Sudan’s civil war killed five Chadian soldiers, as the conflict spilled over into Chadian territory, two sources told the Reuters news agency.

The border closure on Monday comes after a Chadian official told Reuters that clashes on Saturday between the paramilitary Rapid Support Forces (RSF) and militia fighters loyal to Sudan’s military-backed government in the border town of Tina killed five soldiers and three civilians and wounded 12 people.

The conflict in Sudan between the Sudanese Armed Forces (SAF) and the RSF, which erupted in April 2023, has periodically spilled over into Chadian territory, causing casualties and property damage.

Chad’s government said on Monday that the border would remain closed until further notice, citing “repeated incursions and violations committed by forces in Sudan’s conflict."

The move “aims to prevent any risk of the conflict spreading to our soil, to protect our fellow citizens and refugee populations, and to guarantee the stability and territorial integrity of our country”, a government statement said.

The ministry added that exceptions could be made for humanitarian purposes with prior government approval. Chad hosts nearly a million refugees from neighbouring Sudan, which descended into a civil war after a power struggle between the SAF, led by General Abdel Fattah al-Burhan, and the RSF, led by Mohamed Hamdan Dagalo, widely known as Hemedti.

A border guard officer in Tina confirmed the deaths of five soldiers and said additional security measures were needed to protect civilians on the Chadian side.

The two sources, who spoke on condition of anonymity, said more Chadian troops were being deployed to the area.

The SAF and the RSF did not immediately respond to requests for comment.

Last year, a drone attack killed two Chadian soldiers, according to local authorities and a security source, though it was unclear who carried out the attack.

Chad has reportedly served as a transit route for supplies, including weapons and drones, to the RSF, though the Chadian government denies involvement.

Sudan’s civil war has killed tens of thousands of people and forced 11 million to flee their homes, triggering what the United Nations says is one of the world’s worst humanitarian crises.