Sudan’s armed forces said on Wednesday that a number of its officers had been ambushed by “Ethiopian forces and militias” during a security patrol of the border region.

“During the return of our forces from combing the area around Jabal Abutiour inside our territory, they were ambushed by Ethiopian forces and militias inside Sudanese territory, as a result of which lives and equipment were lost,” the army said, adding the attack took place on Tuesday.

The Sudanese army did not specify how many officers were killed. Local residents said that reinforcements were being sent to the area, which is part of the Fashaqa locality where some Ethiopian refugees have been crossing into Sudan.

Fighting erupted on Nov. 4 between Ethiopia’s government and the then-governing party in Tigray, the Tigray People’s Liberation Front (TPLF). Thousands of people are believed to have been killed and more than 950,000 displaced, some 50,000 of them into Sudan, according to United Nations estimates.

Sudanese Prime Minister Abdalla Hamdok visited Ethiopia briefly on Sunday and relayed his concerns about threats to Sudan’s security along its border with Tigray.