At least seven people were arrested in Belgium Sunday in relation to the attacks in Paris Friday, officials said.
The officials added that eight suspects have been identified and that three of them were French nationals living in Brussels.
The attacks, which killed over 130 people and left hundreds injured, including about 90 in critical condition, prompted a state of emergency to be declared in France, which, the government announced, will be in place for the next three months.
French and European officials told the New York Times Sunday that the attackers had communicated with members of the Islamic State group before they executed the attacks in the six different locations in the French capital.
The silliest thing I heard over the last 48 hours is that @Snowden was blamed for the #ParisAttacks. It gets no lower than this.
— Maher Arar (@ArarMaher)
November 15, 201
“The attackers are believed to have communicated using encryption technology, according to European officials who had been briefed on the investigation but were not authorized to speak publicly,” a New York Times report said Sunday.
The officials also said that the attackers had operated with high levels of sophistication suggesting that they could not be simple amateurs inspired by the extremist group, but rather trained and commanded by the Islamic State group's leadership in Syria and Iraq.
ANALYSIS: Paris Attacks: The Backlash of Failing French Policy in Syria
Meanwhile, it seems that at least one suspect is on the run as French authorities said they found the bodies of seven killers but the Islamic State group said there were eight.
An unnamed source close to the investigation told Reuters that a Seat car, believed to have been used by the attackers had been found in the eastern Paris suburb of Montreuil with three Kalashnikov rifles inside.
The French police issued an arrest warrant for Abdeslam Salah, suspected of being the eight person involved in the Paris attacks. Salah is believed to be one of three brothers suspected of participating in the attacks.
French police launched and alert and released the photo of suspect wanted in Paris attacks:
— Mohamed Yehia (@yeh1a)
November 15, 201
Museums and theaters remained closed in Paris for a second day on Sunday, with hundreds of soldiers and police patrolling the streets and metro stations after French President Francois Hollande declared a state of emergency that will be in place for three months.
OPINION: Beirut and Paris: A Tale of Two Terror Attacks
Also, police began questioning the relatives of the first gunman to be identified, Omar Ismail Mostefai, French media reported as the investigation is taking place in three other European countries. Mostefai is a 29-year old French citizen who lived in the city of Chartres, southwest of Paris.
As the investigation into the attacks unfolds, French Muslims, representing more than 6 million or 9 percent of the country's population, have expressed fears over repercussions and Muslims being blamed for the attacks. "When you look like a Muslim, it's tough," said Marjan Fouladvind, an Iranian doctoral student in Paris, told Reuters Sunday.
Don't allow this horrific act allow you to be drawn into the loss of your humanity or tolerance. That is the intended outcome. #ParisAttacks
— Mark Ruffalo (@MarkRuffalo)
November 14, 201
"The way people look at us will change again, and not for the better ... Sometimes it's preferable to be mistaken for a Jew and not a Muslim because then there are fewer problems."
ANALYSIS: 9/11 and the Paris Attacks: Comparing Bush and Hollande Rhetoric
The Islamic State group has said that the attacks were intended as a response to the French operations against the group in Syria and Iraq. One of the assailants reportedly was telling his victims that the attacks were the fault of President Hollande.
Gunmen were heard shouting 'Allahu Akbar' but I did the same tonight, in my room, praying for those killed & their families #Paris
— Ayisha Malik (@Ayisha_Malik)
November 14, 201
The group has also claimed the responsibility for the attack against the French satirical magazine Charlie Hebdo back in January which killed 17 people.
In the weeks that followed, France saw a surge in anti-Muslim acts such as the spraying of graffiti on mosques and insults made against veiled women.
The National Observatory of Islamophobia registered a rise of 281 percent in such incidents in the first quarter of 2015 compared with the same three months of the previous year.