Tunisian authorities have authorized an investigation into whether a group called the Mahdi Organisation exists and carried out the Nice attack, based on social media claims of responsibility, state news agency TAP reported on Friday.
The public prosecutor's office of the judiciary's anti-terrorism court has delegated a specialized security unit to carry out the investigation, TAP reported.
It will seek to learn whether the Mahdi organization exists and the veracity of claims made on social media that it was behind Thursday's attack in the French city, it reported.
The suspect in the attack, in which an assailant shouting "Allahu Akbar" (God is Greatest) beheaded a woman and killed two other people in a church, is Brahim Aouissaoui, a 21-year old Tunisian who had recently emigrated to Europe.
The Italian government was in no way to blame for allowing a Tunisian migrant accused of killing three people in a church in neighboring France to enter Europe, the interior minister said on Friday.
The suspect in Thursday's attack in Nice, Brahim Aouissaoui, reached the Italian island of Lampedusa on Sept. 20 aboard a small boat. He was subsequently moved to the mainland on Oct. 8, and, as with almost all new arrivals, was let free.
The far-right opposition League accused Interior Minister Luciana Lamorgese of failing to prevent people arriving from Africa and said she bore responsibility for the Nice killings.
Lamorgese confirmed that neither the Tunisian authorities nor the Italian intelligence service had flagged Aouissaoui as a potential threat.
"We have no responsibility in this," she told reporters.
Some 27,190 migrants have reached Italy by sea so far this year, up from 9,533 in the same period of 2019, according to official data. Of these, 11,195 have come from Tunisia - by far the largest single national grouping.
Lamorgese went to Tunis in August along with the Italian foreign minister and two EU Commissioners to try to persuade Tunisia to stem the flow. However, she acknowledged it was hard to stop people migrating at present.
"Tunisia is facing a major economic crisis which has made things more complicated. COVID-19 also had a big impact on the country, undermining all efforts at maintaining social cohesion there," she said.
Under current accords, Tunisia agrees to take back a maximum 80 nationals a week. New arrivals are invariably handed expulsion papers but are almost never detained until a flight home can be organized. Instead, many move swiftly out of Italy, often heading to France which has a large Tunisian community.
League leader Matteo Salvini, who as the former interior minister before pulling his party out of government in August 2019, has sought to make political capital out of the attack.
"I apologize to the French people, to the children of the dead and beheaded, on behalf of this incapable government and its accomplices," he said on Twitter.
Lamorgese said a security decree introduced by Salvini had made it harder for the government to deal with migrants because it had closed down immigration centers. "20,000 people had to leave the centers from one day to the next."
A government official also said that a Tunisian man responsible for an attack on a Berlin Christmas market in 2016 had also come to Europe via Lampedusa when another League politician had been interior minister.