PARIS (Reuters) - A high-profile police site was among the potential targets in a foiled terrorist plot, according to a person arrested in France in connection with the plot, two sources close to the investigation said on Wednesday.

A French soldier stands guard near Strasbourg's cathedral in Strasbourg, France, November 21, 2016. REUTERS/Vincent Kessler

France has been under a state of emergency since a wave of Islamist attacks last year, giving police wider powers, and the arrests come at a sensitive time ahead of next spring’s presidential elections in which security will be a major theme.

The sources said the information, for the moment highly tentative, came from one of five people still in custody after simultaneous police swoops in southern port city of Marseille and Strasbourg in northeast France last Saturday night.

One of the sources said the police have also found Internet searches, by some of the suspects, for possible targets, including a theme park in the Paris region.

Two suspects arrested in Marseille - an Afghan and another person - have been released, she said.

Both sources, speaking on condition of anonymity, said one of the suspects had begun to talk to interrogators, notably on the subject of possible targets.

French officials are worried that Islamic State, which is fighting to defend territory it seized in Syria and Iraq, will call on its followers and jihadists returning from the region to increase attacks in the West.

More than 230 people have been killed in attacks on French soil since January 2015, including 130 in coordinated gun and suicide bomb strikes in Paris last November.

As part of sweeps against Islamist radicals, Interior Minister Bernard Cazeneuve said on Wednesday that his government had banned a Muslim charity suspected of financing jailed militants and radicals.

The charity, established in 2010 and called Sanabil, plans to contest the decision and rejected what Cazeneuve said of it, according to Sanabil lawyer Bruno Vinay.

The recent arrests were part of a long-running operation led by the DGSI internal intelligence service which included a wave of arrests last June on the eve of the Euro 2016 international soccer championship that France hosted.

That swoop concerned militant financing while last weekend’s arrests were related to potential hitmen, police sources said.