ISIS is boasting that it carried out a deadly attack Tuesday in France during mass in a Catholic church.
FOX's Simon Owen reports from London:
Two men storming the church in northern France, taking hostages and murdering an 86-year-old priest. The attackers later shot dead by police.
President Francois Hollande has visited the site... He said ISIS has declared war, and we have to fight using all means possible.
It's reported one of the attackers was known to police, after attempting to travel to Syria.
In London, Simon Owen, FOX News.
Follow Simon Owen on Twitter: @bigso
FOX's Courtney Walsh reports from the Vatican: