BRUSSELS—Belgian authorities have opened a terrorism probe following a weekend machete attack on two police officers in the city of Charleroi, the latest assault in what has become a relentless summer-long barrage.

The assailant, who was fatally shot during the attack, was identified Sunday by the authorities as a 33-year-old Algerian man who had been living in Belgium illegally since 2012.

Authorities didn’t disclose any indications of accomplices or large-scale planning behind Saturday’s attack, which left one of the officers with serious injuries to her face and neck. The assailant wasn’t carrying explosives or any other weapon, and while he was known to authorities because of his illegal status in the country, he wasn’t known to have any terror links, federal authorities said. They released his initials, K.B., but not his name.

Islamic State’s news agency Amaq claimed the attack was carried out by one of the group’s “soldiers” in response to strikes by the U.S.-led coalition fighting against it in Iraq and Syria.

Belgian Prime Minister Charles Michel said federal prosecutors had opened a probe into “attempted terrorist murders,” assigning an investigative judge specialized in terrorism cases.