The driver of the truck who killed four people in Sweden had previously tried to join IS, a security source has said.
The Uzbek asylum-seeker who rammed a truck into a crowd of people in Stockholm last week had tried to travel to Syria in 2015 to join the Islamic State group, an Uzbekistan security source said.
The source, who spoke on condition of anonymity, said the suspect, Rakhmat Akilov, was an ethnic Tajik who came under the influence of a Tajik Islamic State cell while living in Sweden.
Mr Akilov, 39, has been living in Sweden since at least 2014.
The source said Mr Akilov was detained at the Turkish-Syrian border in 2015 and deported back to Sweden.
It's thought that in February this year Uzbekistan's authorities had put him on a wanted list for people suspected of religious extremism.
Swedish security police declined to comment on the information, citing the ongoing investigation.
Police believe Mr Akilov, whose asylum application failed and was wanted for deportation at the time of the attack, hijacked a beer truck and drove it into a busy pedestrian street in the Swedish capital before crashing into a department store.
Mr Akilov's lawyer said he had confessed to committing a terrorist crime.
A judge has remanded him in custody for a month while investigations continue.
Swedish security services said Mr Akilov had figured in intelligence reports but they had not viewed him as a militant threat.
Sweden's state migration agency declined to comment on the Uzbekistan security source's remarks.