France has sounded its highest level of counter-terrorism alert following a suspected Islamist attack in which a French teacher was stabbed to death in Gambetta High School in the northern city of Arras. Police arrested the man, identified as Mohammed Moguchkov, who had cried the Arabic phrase "Allahu akbar!" (God is greatest), AFP reported citing the preliminary elements of the investigation. French President Emmanuel Macron denounced the incident as an act of "Islamist terror". With the alert in place, France is mulling to deploy nearly 7,000 soldiers to keep a check on parts of the country.


France increased its alert level to the highest position after a security meeting chaired by Macron on Friday, the prime minister's office told AFP.


"This school was struck by the barbarity of Islamist terrorism," Macron said after visiting the school, adding that the victim had "probably saved many lives" with his courage in blocking the attacker, as quoted by AFP.


According to BBC, Interior Minister Gérald Darmanin said there was "no doubt" a link between the Arras attack and the Israel-Hamas conflict. The 20-year-old accused is a Russian national and is of Chechen origin. Reports say that he was a former students of the school and teachers were alarmed by his extremist language.


Police said Moguchkov was known to the security services for his involvement with Islamist extremism, the report added.


The deployment of the soldiers from Operation Sentinelle will be completed by Monday evening, according to the Elysee presidential palace, as quoted by AFP. Notably, Sentinelle is a French military operation consisting of 10,000 soldiers, 4,700 police and gendarmes deployed since the aftermath of the January 2015 attacks to protect the country from terrorism. Meanwhile, as per AFP, Macron claimed another attempted attack in another region had been foiled by security forces.


So far, eight people have been taken into on Friday, a police source told AFP. Apart from the attacker, it added, several members of his family were arrested "for the purposes of the investigation."


The national anti-terrorist prosecutor announced that it has opened an investigation into the attack.