Who were the suspects behind the Paris attacks?

French authorities are carrying out raids across the country to rein in the network responsible for orchestrating Friday's terrorist attacks in Paris that killed at least 129 people.

Three teams staged coordinated attacks at six locations throughout Paris late Friday, including a concert hall, the Stade de France and at least two restaurants.

It's possible that suspects who were directly involved in the attacks remain at large, a French counterterrorism source close to the investigation told CNN.

ISIS claimed responsibility for the massacres and, in response, France has carried out air strikes on targets in the militant organization's stronghold in Raqqa, Syria.

As investigators piece together information about who could be on the loose, details are emerging about several of the seven attackers who authorities say were killed.

Here's what we know about the suspected attackers:

Bilal Hadfi

Sources say Bilal Hadfi was one of the three suicide bombers at a stadium in Paris

Status: Dead

Residence: Belgium

Suspected of: Stadium suicide bomber (Stade de France)

Bilal Hadfi has been identified by several sources as one of the three suicide bombers who struck outside the Stade de France.

Hadfi, a Belgian resident who was 19 or 20 years old, is thought to have fought in Syria where he went under the names "Abu Moudjahid Al-Belgiki" and "Bilal Al Mouhajir," Belgian terror expert Guy van Vlierden told CNN's Tim Lister and Paul Cruickshank.

Hadfi appears to have traveled to Syria as recently as this past spring, van Vlierden said, citing analysis of Hadfi's social media postings and other communications.

Hadfi is seen holding up his index finger in a screenshot from a now-deleted video post from his Facebook account calling for attacks on the West.

'Ahmad al Muhammad' (false name)

Status: Dead

Residence: Unknown; immigrated with Syrian refugees

Suspected of: Stadium suicide bomber (Stade de France)

One of three bombers who detonated themselves at the Stade de France late Friday arrived on the Greek island of Leros on October 3 among numerous Syrian refugees, CNN's Christiane Amanpour reported, citing an unnamed French senator who was briefed by the Ministry of the Interior.

Suicide bomber smuggled in with refugees 06:11

This man held an emergency passport or similar document and falsely declared himself to be a Syrian named Ahmad al Muhammad, born on September 10, 1990, the senator said. The man was allowed to enter Greece on October 3 and, from there, moved to Macedonia, then Serbia and Croatia, where he registered in the Opatovac refugee camp, the lawmaker said.

Eventually, he made his way to Paris, where he was one of three men who blew themselves up at the Stade de France.

Identity unknown

Status: Dead

Suspected of: Stadium suicide bombing

Not much is known about the third suicide bomber at the Stade de France. The unnamed French senator said two of those who detonated themselves at the stadium carried false Turkish passports.

Ismael Omar Mostefai

Status: Dead

Residence: Chartres, France

Suspected of: Bataclan concert suicide bomber

Ismael Omar Mostefai has been identified as one of the three suicide bombers armed with assault rifles at the Bataclan concert hall, the deadliest site where at least 89 people were killed.

Paris prosecutor Francois Molins described Mostefai as a 29-year-old French citizen with a criminal record from the southern Paris suburbs. He was identified by fingerprints and was believed to have been radicalized in 2010 but had never been accused of terrorism, Molins said. Mostefai lived in the French town of Chartres at least until 2012, according to Jean-Pierre Gorges, the mayor of Chartres, who is also a member of Parliament.

Salah Abdeslam

International manhunt for Paris suspect 02:51

Status: On the loose

Residence: Belgian-born, French national

Suspected of: Unclear

Belgium has issued an international warrant for Salah Abdeslam, and French police released his photo and warned people not to interact with him, saying he is dangerous.

Investigators haven't said much about how they believe Abdeslam is tied to Friday's terror attacks in the French capital.

Jean-Pascal Thoreau, a spokesman for Belgium's Federal Prosecutor, said Abdeslam is one of three brothers suspected of involvement in the attacks. One of the brothers was killed in the attacks, and another was arrested by Belgian police, Thoreau said.

Salah Abdeslam, a Belgium-born French national, had been questioned by French police earlier but was not detained, a source close to the investigation into the Paris attacks said.

He was driving in the direction of the Belgian border when stopped by police and questioned a few hours after the attacks, the source said. Now, his whereabouts are unknown.

Map: Paris terror attacks