Police are investigating two suspicious deaths in a French prison known for its large population of Islamic extremists.

Police say they are looking into two incidents, both occurring within days of each other, and investigating potential murder suspects in the Fleury-Mérogis prison in the department of Essonne outside of Paris, 20 Minutes reports.

According to investigators, the first victim was murdered on April 5th following a mass brawl. The 39-year-old, who had been incarcerated for two months, was set to be released on April 7th but ended up brain dead as a result of injuries sustained after being attacked, and died earlier this week.

The fate of the second victim is less clear as he was found dead in his cell on April 8th from an unknown cause. According to a source within the prison guards union, the man had visited the prison doctor the day before after vomiting in his cell. He was found the following day after another inmate used an emergency telephone to alert the guards.

Fleury-Mérogis prison has become notorious across the country for its high population of radical Islamic extremists and houses several of the country’s most dangerous terrorists, including Salah Abdeslam, one of the terrorists who took part in the 2015 Bataclan massacre.

Paris Attacker Greeted with Cheers in French Prison https://t.co/etQ6wp9F27 pic.twitter.com/BThQtmJOzU — Breitbart London (@BreitbartLondon) April 29, 2016

When Abdeslam was brought to the prison in 2016, he was greeted with cheers from inmates, though other radicals jeered him for not blowing himself up and becoming a martyr.

The prison has also been a hub for radicalisation, with Islamic terrorist Karim Cheurfi, who killed a police officer on the Champs Elysees in Paris in 2017, spending time in the prison in 2002 where he is said to have been radicalised.

Other prisons in France also have substantial Islamic radical populations, including Fresnes prison, south of Paris, where investigators found a pair of radicals plotting a terrorist attack in their cells and using smuggled mobile phones to communicate directly with members of the Islamic State terror group.