French police have arrested a 24-year-old Algerian computer student suspected of planting a bomb in Lyon last week that wounded 13 people, authorities said Monday.

Three other people were also arrested in connection with the case, which is being treated as a terrorism investigation.

A man was spotted by security cameras leaving the explosive device, with screws and metal balls packed into a paper bag, in a pedestrian shopping street in the central French city on Friday a minute before it exploded.

Sources close to the investigation said the Algerian student did not have police records, while the other three detainees included his mother and younger brother, who is a high school student.

Police found the man thanks to security camera footage, Lyon Mayor Gerard Collomb told BFM TV station.

Security camera footage showed the partially masked suspect wheeling a bicycle to the scene, before leaving a bag outside a branch of a popular bakery chain.

DNA traces were found on the remains of the parcel, according to a source close to investigation.

Another source said police arrested the suspect on the street after having tailed him.

They decided not to arrest him at his apartment, the source said, for fear that there could still be some triacetone triperoxide (TATP), the powerful but unstable homemade explosive that was used in the attack.