Paris (CNN) Security forces sealed off streets in a Paris suburb Monday, and a bomb squad headed to the scene after investigators found a possible suicide vest in a garbage can.

Paris police told CNN that authorities were trying to determine whether the article found in the Paris suburb of Montrouge contained explosives. CNN affiliate BFMTV reported that the item, which resembled a suicide vest, contained bolts and TATP, the same explosive found in the suicide belts used by Paris attackers

Could there be a connection between the garbage-can find and the November 13 series of shootings and bombings that killed 130 people in Paris?

Authorities haven't said. But BFMTV and the French newspaper Le Monde reported Monday night that suspect Salah Abdeslam 's cell phone was tracked to the area soon after the attacks.

"The big question is going to be: Is this the suicide vest that Salah Abdeslam was tasked to use?" CNN terrorism analyst Paul Cruickshank said.

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And there are other questions, too, Cruickshank said. If it was a vest belonging to Abdeslam, why would it just have been discovered 10 days after the attacks? And if it wasn't, then whose is it?

"It is possible that somebody else may have jettisoned it, an attacker that we don't know much about at this point," Cruickshank said. "So they'll be doing all sorts of forensics, trying to establish who this belonged to, and that will be a huge priority for French investigators."

Suspect charged in connection with Paris attacks

Abdeslam is thought to be using a support network in Belgium to avoid being captured, more than a week after an international arrest warrant was issued for his arrest in connection with the Paris terror attacks.

Sources in France close to the ongoing investigation believe Abdeslam could not have survived a week on the run without help. They say that extensive raids in Belgium on Sunday and Monday , in which 21 people were detained in several locations, targeted individuals suspected of a role in the network that organized the attacks.

Fifteen of those arrested have since been released. Authorities charged one man with participating in the activities of a terrorist group in connection with the Paris attacks.

French authorities have said the Paris attacks were organized in Belgium, with jihadists taking advantage of intelligence gaps and the absence of border controls between the two countries to slip into France undetected.

Several of the men believed to have taken part in the attacks have strong ties to Brussels, notably its suburb of Molenbeek, which has a history of links with terrorism plots

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So far, the operations in Belgium haven't uncovered Abdeslam , and there's "unprecedented concern" among Belgian authorities, Cruickshank said.

The nation's prime minister said Brussels will remain at the highest terror level until at least next Monday. And in Brussels, fears of a terror attack will keep schools and the metro closed until Wednesday at the earliest, Belgian Prime Minister Charles Michel announced Monday.

"The worry is that there's another attack team out there, that they have explosives, that they have weapons," Cruickshank said. "Belgian police don't have a handle on where these guys are and that's why they're shaking the tree so hard."

The concern stretches beyond Belgium's borders. A new U.S. intelligence bulletin warns law enforcement to review training for dealing with active shooters after the Paris attacks showed signs of prior surveillance, tactical planning and military-style training.

According to the bulletin, a cell phone recovered from a garbage bin near the scene of the Bataclan concert hall and believed to belong to one of the terrorists contained a map of the theater.

The bulletin, which was described to CNN and confirmed by other U.S. officials, advises local law enforcement to be on the lookout for suspicious people conducting surveillance of potential targets.

Jets from French aircraft carrier target ISIS

Meanwhile, France launched its first airstrikes from an aircraft carrier against ISIS on Monday as President Francois Hollande began a diplomatic offensive to persuade world leaders to join a coalition fighting the terror group.

Warplanes took off from the aircraft carrier Charles De Gaulle in the eastern Mediterranean and attacked ISIS targets in Iraq and Syria, the French Defense Ministry said

The latest wave of airstrikes come as the French President pushes to form a multi-national force to fight ISIS after the terror organization claimed responsibility for the November 13 attacks that left 130 dead in Paris.

Hollande will visit Washington to meet with U.S. President Barack Obama on Tuesday, then meet with German Chancellor Angela Merkel on Wednesday and travel to Moscow to meet with Russian President Vladimir Putin on Thursday.

Hollande met with British Prime Minister David Cameron earlier Monday and they agreed to a pan-European effort for stronger external EU border controls, a more effective way of screening people and greater information sharing, Cameron said.

Cameron will make a case for the United Kingdom to start bombing ISIS positions in Syria on Thursday, he said Monday as he presented the country's defense spending review in Parliament.

Russia may be showing signs of warming up to a coalition with France. The Russian Defense Ministry released photos on Monday that showed the words "For Paris" written on Russian missiles that will target ISIS positions.