French police say thieves stole a computer and a police armband from a car used by aides to presidential candidate Francois Fillon.

Police commander Christophe Voreux said Thursday that the two parliamentary aides and a member of Fillon's security detail were dining in a fast-food restaurant when someone broke into their hire car parked outside.

The theft Tuesday night near Lille airport in northern France is being investigated.

The government previously announced that security around candidates and the election has been stepped up ahead of Sunday's first-round vote. Earlier this week in Marseille, police arrested two alleged Islamic extremists who were suspected of planning an attack.