Chad's government said on Monday it was closing the border with Sudan until further notice, following several clashes between Chadian soldiers and armed groups involved in the civil war across the frontier.
"This decision follows repeated incursions and violations committed by the forces involved in the conflict in Sudan on Chadian territory," Communications Minister Mahamat Gassim Cherif said in a statement, adding that he wanted to halt "any risk of the conflict spreading" to his country.
Sudan's paramilitary Rapid Support Forces have been fighting government troops for almost three years in a conflict that has killed tens of thousands of people and forced 11 million to flee their homes, triggering what the UN says is one of the world's worst humanitarian crises.
The paramilitaries have conducted several operations near the Chad border and at least nine Chadian soldiers have been killed in separate incidents since December.
Monday's statement said Chad "reserves the right to retaliate against any aggression or violation of the inviolability of its territory and its borders".
"Cross-border movements of goods and people are suspended," the text said, adding that "exceptional exemptions" for humanitarian reasons would still be possible.
