PARIS, France (AFP) — French police stopped an apparent bomb attack outside a United States bank in Paris early Saturday when they arrested a person about to set off a homemade explosive device, officials and sources close to the case told Agence France-Presse (AFP).

The incident occurred around 3:30 a.m. in front of a Bank of America building in the chic 8th arrondissement, a couple of streets from the Champs-Elysees.

Police grabbed the suspect just after he placed a device, made of five liters of liquid, believed to be fuel, and an ignition system, one of the sources said.

After his arrest, the suspect claimed to be both a minor and a Senegalese citizen, according to a police source, who cautioned that the authorities were still verifying his identity.

He was accompanied by a second person, who took flight when officers arrived to arrest the pair.

The ignition component had 650 grams of explosive powder in it, according to an initial assessment. The whole device was taken to the Paris police’s forensics lab for full analysis.

Prosecutors at France’s counter-terrorism office told AFP they had immediately taken over the investigation, and confirmed the suspect caught was in police custody.

It said the probe it had launched was into “attempted damage by fire or other dangerous means in connection with a terrorist undertaking” and a “terrorist criminal conspiracy.”

Both the Paris judicial police and France’s domestic intelligence service, the General Directorate for Internal Security, were involved in the investigation, the office told AFP.