Two brothers may have been implicated in the terrorist attacks in the French capital, and one may still be at large, according to reports.

French media is reporting that one of the brothers died in the attacks. Le Figaro reports that the other one may also have died while taking part in the atrocities or could be on the run.

A third brother was arrested in Belgium and questioned before being released.

Earlier it was reported that at least three of the suicide bombers involved in the atrocities were French.

Two of them were living in Brussels and the other was Ismael Omar Mostefai, one of the terrorists inside the Bataclan concert hall where at least 89 people died.

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As investigators try to identify the seven attackers - and any potential accomplices - they are also examining two passports found at the scenes of the attacks which apparently belong to a Syrian and an Egyptian.

In other developments:

:: A Seat car found abandoned in the Paris suburb of Montreuil is also at the centre of the probe after three Kalashnikov rifles were reportedly found inside.

:: Officials could not confirm if this was the same Seat spotted at the scene of attacks on Le Carillon bar and Le Petit Cambodge restaurant.

:: The French broadcaster BFM TV has said a man who hired a VW Polo car used in the attacks is still being hunted by police.

:: At least seven people have now been detained in Belgium and on the Belgian-French border, but Belgian officials have declined to comment on reports the attacks were largely planned in Brussels.

:: An unnamed French official said a brother of one of the seven attackers was among those facing questioning.

The Mayor of Chartres said Mostefai, 29, was killed carrying out one of Friday night's six attacks.

French newspaper Le Monde said he was identified from a print from his severed finger, discovered after he detonated a suicide vest inside the Bataclan .

Mostefai was born in Courcouronnes, Essonne, and lived in Chartres, southwest of Paris.

He had a criminal record and was known to security services but had not spent time in jail or been linked to any extremist groups.

French news website RTL said Mostefai's brother turned up at a police station in the south of Paris explaining that he had not been heard from in months.

Former neighbours described Mostefai as "a bloke like any other".

The Paris prosecutor's office said some of Mostefai's family members had been held, without giving details.

Three teams of attackers in identical explosives vests appear to have co-ordinated the "act of barbarism" that left a total 129 people dead and 352 injured across the French capital.

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A French citizen is among three people detained at the Belgian border, while others were held in police raids in Molenbeek, an immigrant area of Brussels.

Belgian Prime Minister Charles Michel said at least one of those held in Molenbeek was thought to have spent the previous night in Paris.

Two cars registered in Belgium were impounded close to scenes of the violence in Paris, including the Bataclan.

Molenbeek has been connected with two attacks in France this year - the Islamist killer at a kosher shop in Paris in January got his guns in the district, as did the attacker overpowered on a Brussels-Paris train in August.

Islamic State has claimed responsibility for Friday's near-simultaneous attacks, which it blamed on France's involvement in the US-led airstrikes on IS territory in Syria and Iraq.

The assailants were heard speaking of both countries during the atrocities.

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Syrian and Egyptian passports were found near the bodies of two of the attackers, with Greek officials suggesting that two of the suspects may have arrived in the European Union through Greece in recent months.

Paris prosecutor Francois Molins confirmed a Syrian passport found at the site of one of the attacks belonged to a Syrian citizen born in 1990, but he was unknown to the security services.

Serbian news site Blic has published an image purporting to be the Syrian passport, which has the name Ahmed Almuhamed, 25.

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