PARIS >> French authorities have detained two more people in the investigation into the Bastille Day truck attack on the Mediterranean city of Nice that killed at least 84 people.

An official with the Paris prosecutor’s office, which oversees national terrorism investigations, said a man and a woman were detained Sunday morning in Nice but provided no details on their identities. The official said five people detained previously remain in custody.

Authorities are trying to determine whether truck driver Mohamed Lahouaiej Bouhlel, a 31-year-old Tunisian who had lived in Nice for years, was acting alone in Thursday night’s deadly attack.

The Islamic State group has claimed responsibility for the attack, though people close to him noted no signs of radicalism, just anger.

With scores still hospitalized, France’s health minister is visiting Nice.