Souad Merah’s brother, a self-styled extremist, raised fears over the threat of homegrown terrorism in France in 2012, after killing seven people during a shooting spree in the southern French cities of Toulouse and Montauban. Police eventually cornered the young man at his home in Toulouse, where he died in a hail of bullets following a 32-hour siege on his apartment.

On Thursday, police raided Souad Merah’s home, also in Toulouse, after the counterterrorism branch of the Paris prosecutor’s office opened a preliminary investigation into her suspected connections to a terrorist organization. Upon entering the apartment, however, they found no trace of Merah or of her four young children.

An anonymous interior ministry official later said that the government believed Merah had left France for Syria – a suspicion Cazeneuve made public on Friday, despite claims by both the young woman’s mother and lawyer she was away on holiday in Tunisia.

“Souad Merah took a Barcelona-Istanbul flight May 9, a Turkish Airlines plane,” Cazeneuve told French radio Europe 1 on Friday, adding that she then boarded a flight from Istanbul to the southern city Gaziantep, which lies near Turkey’s border with Syria. “There are strong suspicions that she is in Syria.”

The interior minister said Merah had taken her children with her, and is believed to have gone to join her partner who is “possibly in Syria”.

Known for her radical beliefs, Merah came under fierce criticism in late 2012 after declaring she was “proud” of her brother Mohamed “for fighting to the end,” during a conversation with another sibling that was secretly recorded and then broadcast by French television M6. Merah was placed under investigation for condoning terrorism, but she later came forward to publicly condemn her brother’s actions and the inquiry was eventually dropped.

The French government has expressed growing alarm in recent months over the number of its citizens travelling to Syria to take up arms alongside Takfiri insurgents battling Syrian armed forces. There are fears that those who return to France after fighting abroad may pose a potential security threat.

Just last month, the government announced a string of measures to deter French nationals – in particular youth – from heading to Syria, including a hotline families can call to report their suspicions to the authorities.

NTJ/MB