PARIS (AP) — French authorities have filed preliminary charges against two people of plotting an attack days before a tense presidential election.

The Paris prosecutor's office said Sunday the two men are being kept in custody pending further investigation. They were given preliminary charges Sunday of "association with a terrorist enterprise with plans to prepare one or several attacks," and weapons and explosives charges.

The two suspected Islamic radicals were arrested Tuesday in Marseille and police seized guns and explosives. The target of their potential attack is unclear, though presidential campaign teams were warned about the threat.

Meanwhile, prosecutors said that investigators have released three people without charge after they were detained in an attack on Paris' Champs-Elysees. The attacker was killed but three people in his entourage were detained for two days.