French soldiers, part of France's national security alert system "Sentinelle", patrol near the Cathedral in Arras.
French soldiers, part of France's national security alert system "Sentinelle", patrol near the Cathedral in Arras as France has raised the security alert for French territory to the highest level after the knife attack in the city of Nice, France.

Police in France have detained a second suspect in connection with Thursday’s deadly knife attack at a church in the city of Nice. 

The suspect is a 47-year-old man believed to have been in contact with the attacker the night before the attack at Notre Dame Basilica, according to a judicial official, who was not authorized to be publicly named.  

In Tunisia, authorities are reportedly investigating whether a group called the Mahdi Organization carried out the attack. The state news agency TAP reported Friday investigators were also trying to determine whether the group exists and that the probe is based on claims of responsibility on social media. 

A picture of Brahim al-Aouissaoui, who is suspected by French police and Tunisian security officials of carrying out Thursday's attack in Nice, is seen in this undated photo provided by his family on Oct. 30, 2020.

Authorities have identified the attacker as a Tunisian national, 21-year-old Ibrahim Issaoui. He was shot and seriously wounded by police Thursday and remained hospitalized Friday in life-threatening condition.  

Three people were killed in Thursday’s attack. French anti-terrorism prosecutor Jean-Francois Ricard said a 60-year-old woman and a 55-year-old man had their throats slit, while a 44-year-old woman was stabbed several times. 

Brazilian media identified the stabbing victim as a Brazilian national, Simone Barreto Silva. Ricard said she was able to flee the church but died after collapsing at a nearby restaurant. 

Issaoui was not on Tunisia’s list of suspected militants and was not known to French intelligence services.  

Ricard said Issaoui arrived on the Italian island of Lampedusa on September 20 and traveled to Paris on October 9.

He said Issaoui was carrying a copy of the Quran. The knife used in the attack was found near him and two other knives not used in the attack were found in a bag that belonged to him. 

French leaders have termed Thursday’s incident an Islamist terrorist attack and raised the country’s security alert to its highest level. President Emmanuel Macron said he would increase the number of troops deployed to protect schools and churches from 3,000 to 7,000. He vowed the country will not give in to any terrorism.