Fransk politi har arrestert fire personer som de mener planla å angripe militære installasjoner som ledd i jihad.

Security forces prevented an attack on French military installations this week by arresting four people whose leader had links to jailed jihadists, Interior Minister Bernard Cazeneuve said on Wednesday.

According to a source close to the situation, the attackers had planned to act in January 2016 and were targeting a senior military official in the south of France.

The four were aged between 16 and 23 and arrested in different places around France, the minister said. One was ex-military, he added.

Tirsdag var det brann i to petrokjemiske fabrikker nær Marseille og politiet sier nå at de var påsatt.

French authorities have also confirmed that two fires that broke out at a petrochemical facility near Marseille on Tuesday were started deliberately. No motive has been established for the arson attacks, and Cazeneuve said no link had been made between the incidents.