Updated

Officials are investigating threats issued by a radical Islamic group against France (search) and its overseas interests, the Justice Ministry said Tuesday.

The group identified itself as the "Servants of Allah the Powerful and Wise" (search) in a letter addressed to Prime Minister Jean-Pierre Raffarin and sent to several newspapers, the Justice Ministry said in a statement. The group was not previously known to French authorities.

"A heavy offensive will take place on the grounds of the allies of Satan and we are going to plunge France into terror and remorse," the letter stated, according to Le Parisien newspaper.

The letter, which threatened France and its overseas interests, was signed in the name of "Commando Movsar Barayev," the Chechen rebel who allegedly led a hostage-taking raid on a Moscow theater in October 2002. Barayev was killed when Russian special forces stormed the theater.

Raffarin urged France to remain calm, saying authorities had no immediate plan to increase security, already elevated after last week's attacks in Madrid.

French President Jacques Chirac (search), just hours before the threat was made public, told a news conference that France had not received any specific threats.

Officials did not immediately disclose the nature of the threats.

France's tough opposition to the war in Iraq was initially seen as having won Paris favor in the Muslim world, but that faded with France's plan to ban Islamic head scarves and other religious apparel in schools.

"With this head scarf law, you have participated in an unjust aggression," said the letter, which was written in French under an Arabic-language letterhead. "You have decided on your own to put yourself on the list of Islam's worst enemies."

The letter said the group was waiting for "three signs" before coming forward. It cited the Feb. 10 National Assembly vote in which lawmakers overwhelmingly backed the head scarf ban and a "clear and explicit signal" from Usama bin Laden's (search) top lieutenant, Ayman al-Zawahri (search). The letter said the group could not reveal its third "signal."

A U.S. official in Washington, who spoke on the condition of anonymity, was not personally aware of the group "Servants of Allah the Powerful and Wise."

In February, an audiotape purportedly from al-Zawahri criticized France's decision to ban religious symbols from schools, legislation seen by many in the Arab world as anti-Muslim.

Al-Zawahri, an Egyptian-born physician, is thought to be with bin Laden in hiding somewhere along the Pakistan-Afghanistan border. The tape was aired Al-Arabiya, the Dubai-based Arab-language satellite channel.

In recent weeks, French authorities have received terror threats from another little-known group that calls itself AZF. The group claims to have planted nine bombs along the country's rail network and has threatened to explode them unless it is paid millions of dollars.

Information from AZF led to the recovery Feb. 21 of an explosive device buried in the bed of a railway line near Limoges in central France.

Since the Sept. 11 attacks against the United States, France has arrested dozens of terror suspects.

Authorities dismantled a terror cell in 2002 with ties to Chechen rebels and Al Qaeda that planned bomb or toxic gas attacks in France and Russia. Among the suspected targets was the Russian Embassy in Paris.

The American Embassy in Paris was the target of a foiled bomb plot in 2001. Franco-Algerian Djamel Beghal, a prime suspect in the plot, was arrested in the United Arab Emirates in July 2001 and handed over to French custody.

Shoe-bomber Richard Reid (search), a British convert to Islam, was aboard an American Airlines flight from Paris to Miami in Dec. 2001 when he tried but failed to detonate explosives in his shoes.