The Uzbek national suspected of mowing down pedestrians in Stockholm last week had tried to join the ranks of the Islamic State jihadist group in Syria, an Uzbek source told Russian agencies.
The 39-year-old suspect, Rakhmat Akilov, "fell under the influence of emissaries of the Tajik cell of the Islamic State, making attempts to take part in combat in Syria on the side of the fighters," an unnamed law enforcement source in the Central Asian state said.
According to the source, Akilov attempted to cross Turkey's border with Syria in 2015 but was detained.
"Given his refugee status he was deported back to Sweden," the source said.
The source added that Uzbek authorities had added Akilov to an international wanted list in late February after a criminal case on "religious extremism" was opened against him.
Akilov on Tuesday confessed to a "terrorist crime" for the truck attack that killed four people and injured 15 others on Friday, his lawyer said.
He had reportedly said he had received an "order" directly from IS to carry out the attack, according to Swedish media reports.
Akilov, a construction worker who had been refused permanent residency in Sweden, was arrested several hours after the attack.
He had gone underground after his application for Swedish residency was rejected last year, police said.