French police on Monday arrested two more people over an apparent bid to set off a homemade explosive device outside a Bank of America branch in Paris, bringing the total in custody to five, prosecutors said.
The arrests follow an incident early Saturday morning when police arrested a first suspect after he placed a device outside the US financial institution near the Champs-Elysees.
The two individuals detained on Monday are adults, according to a source following the case, who spoke on condition of anonymity.
The national anti-terror prosecutor's office (PNAT) told AFP that the three minors arrested over the weekend in connection with the case had their detentions extended.
Interior Minister Laurent Nunez suggested on Saturday that the war in the Middle East might have motivated the attempted attack.
The suspect who placed the device was accompanied by a second person, who appeared to be taking photos and videos with a mobile phone but fled when police arrived.
The device contained five litres of liquid (nearly nine imperial pints) believed to be fuel and an ignition system, a source close to the investigation said.
Police said the suspect arrested early Saturday outside the bank had told them he was a minor and from Senegal. They were working to verify his identity.
According to a police source, the first suspect said he had been recruited through the Snapchat app to carry out a bombing in exchange for 600 euros ($688).
The PNAT told AFP on Saturday it had launched a probe into "attempted damage by fire or other dangerous means".
The incident came after more than a month of US and Israeli bombardment of Iran.
The war has escalated into a regional conflagration, with Iran retaliating by attacking Gulf states, sending energy markets into a tailspin and threatening the world economy.
The French government and security services have said that while they do not believe France itself is a target, US and Israeli interests on its soil might potentially be singled out.
Nunez said he did not know who was behind the incident but added that it might have been "proxies" linked to Iran.