Update as of 8 a.m. EDT: A second man reportedly involved in an attack on a gas factory in southeastern France has been arrested. The man was apprehended at his home in Saint-Quentin-Fallavier, the town where the factory is located, BBC reported, citing local media. The man is reportedly suspected of driving the vehicle that was rammed into the factory entrance.

French Interior Minister Bernard Cazeneuve reportedly said that authorities are still trying to identify the victim, whose severed head was found pinned to the factory’s entrance.

Air Products, the factory owner, confirmed in a statement that the man killed was not an employee.

Update as of 7:33 a.m. EDT: Several arrests have been made after an attack on a factory in southeastern France killed one person and wounded two others, the Associated Press reported, citing a senior French official.

Meanwhile, Agence France-Presse reported, citing France's interior minister, that one of the suspects arrested following the attack has links to the Salafist movement.

The arrested suspect was identified as Yacine Sali, who is known to police and was reportedly on a security watch list after being investigated in 2008 but has no criminal record, the BBC reported, citing France's interior minister. However, his identify has not yet been officially confirmed. 

Update as of 7:13 a.m. EDT: French President Francois Hollande, speaking from Brussels, reportedly announced that there may have been a second person involved in the attack on a factory in southeastern France Friday that killed one person and injured two people. Suspected accomplices of those involved in the attack are being held by police, according to reports.

"It is a terror attack, there is no doubt about that," he said, in a statement, BBC reported, adding: "This attack was carried out from a vehicle driven by one person, perhaps accompanied by another, which rammed its way at high speed into this establishment which contained bottles of gas."

Hollande, who is expected to return to France from an EU summit, has reportedly called for a high level defense council meeting for Friday afternoon. Hollande ended his statement by calling for action over the attack and referring to Islamist attacks in the country in January, which included an attack on the Paris offices of French satirical magazine Charlie Hebdo.

"We all remember what happened before in our country… There is therefore a lot of emotion. But emotion cannot be the only response. [What is needed] is action, prevention and deterrence," Hollande reportedly said.

Update as of 6:40 a.m. EDT: French officials said that two flags -- one white and one black -- both with Arabic inscriptions, were found at the scene of an attack on a factory in southeastern France that is suspected to be linked to Islamist terrorists, the Associated Press reported, adding that police were searching for anyone else involved in the terror attack.

French President Francois Hollande reportedly described the attack as being of "a terrorist nature" and that all measures were being taken to avoid any further attacks.

British Prime Minister David Cameron reportedly spoke to Hollande on Friday to convey his sympathies over the attack.

"The Prime Minister has just spoken to President Hollande to express his sympathies for what looks like an appalling incident there," a source said, according to Reuters. "It clearly looks an extremely concerning situation and our thoughts are with all those affected by it."

Original story:

An attack on a gas factory near Grenoble, in southeastern France on Friday, left one person dead and injured several others, local media reports said. The attack began mid-morning after two men crashed a car into gas canisters at the factory entrance, causing explosions, the Associated Press reported, citing two French officials.

The factory belongs to Air Products, a U.S.-based industrial gases technology company, Reuters reported, citing a spokeswoman for Air Liquides, a French company in the same sector. The French interior minister was reportedly headed to the scene of the attack, Reuters added.

France's anti-terror prosecutor said, in a statement, that the attack was carried out by "a terrorist group," AP reported. 

A decapitated body was reportedly found at the scene of the attack, Agence France-Presse (AFP) reported, adding that one of the attackers was taken into custody. A flag bearing Islamist inscriptions was found near the body, according to local reports, but the motive of the attack remains unclear. Le Dauphiné Libéré, a local news outlet, reported that the man arrested was known to intelligence services. Officials reportedly said that it was unclear what happened to the second attacker.

One of the suspects was reportedly carrying a black Islamist flag, AFP reported, citing a legal source, and added that Arabic writing was found on the severed head, which was pinned to the factory gate. France has tightened security measures on "sensitive" sites after the attack, AFP added.

French authorities have opened a terrorism investigation into the attack, AP reported. Meanwhile, an official reportedly said that President Francois Hollande is returning to France from the European Union summit in Brussels after news of the attack.