Islamic State fighters in Libya allegedly have seized large amounts of chemical weapons, including mustard gas and the nerve agent Sarin, the Libyan military charged. “Unfortunately [chemical weapons] exist in locations known to the militias, who have seized large amounts of them to use in their war against the [Libyan] army,” a Libyan military official told the London daily Asharq al-Awsat.

ISIS fighters near Tripoli have begun testing the weapons that reportedly once belonged to the former regime of Moammar Gadhafi. “Before his death, Gadhafi left approximately 1,000 cubic tons worth of material used for manufacturing chemical weapons and about 20,000 cubic tons of mustard gas,” the military official said.

The weapons are likely 10 years old and in a degraded state, but remain dangerous, former British Army officer Hamish de Bretton-Gordon told The Daily Mail Sunday. "While we don’t know how much IS has acquired, and though the Libyan Sarin dates back to the Gadhafi era, it would still have a toxicity and pose a danger," he said. "Libya is virtually Europe and so the fear factor from a European perspective is huge. I should think the security forces will be watching this situation very closely."

Last year, Libyan officials said they had destroyed the last known stockpile of chemical weapons from Gadhafi's regime. “Libya is totally empty of any presence of chemical weapons ... which could pose a threat to the safety of people, the environment or neighboring regions,” Foreign Minister Mohammed Abdelaziz said at the time.

ISIS already has used chemical weapons, including chlorine in Iraq. Islamic State fighters have seized territory in Syria and Iraq in recent months and now are apparently targeting Libya. The North African nation has lacked a strong government since Gadhafi was toppled four years ago.

Last week, Islamic State fighters released a video purporting to show the beheading of 21 Egyptian Coptic Christians kidnapped in Libya. In the video, militants dressed in black beheaded the captives on a beach near Tripoli.