The suspect in Friday's deadly truck attack in Stockholm posted videos of ISIS atrocities on Facebook and "liked" a picture showing the bloody aftermath of the 2013 Boston Marathon bombings, a Swedish newspaper reported.
The Aftonbladet newspaper said the suspect was a 39-year-old man from Uzbekistan who had lived in one of the Swedish capital's southern suburbs. The newspaper quoted a friend of the arrested man who said the suspect was a father of four and worked in construction.
"He never talked politics or religion," the friend said. "The only thing he talked about was getting more jobs so he could send money home to his family."
Four people were killed and 15 others were injured Friday when a hijacked beer truck plowed into pedestrians at a central Stockholm department store. Swedish Prime Minister Stefan Lofven said his country had been "attacked" and described the incident as an "act of terror."
"The country is in a state of shock," he said. "The aim of terrorism is to undermine democracy. But such a goal will never be achieved in Sweden."
The Aftonbladet report quoted a police source who said authorities have "very good evidence" against the suspect. The arrested man was wearing the same clothes as a man seen in a photo distributed by police. The suspect was also covered in broken glass.
The stolen beer truck traveled for more than 500 yards along a main pedestrian street known as the Drottninggatan before it smashed into a crowd outside the upscale Ahlens department store about 3 p.m. local time (9 a.m. ET) It came to rest in the entrance to the building. TV footage showed smoke coming out of the store after the crash.
Police believe the suspect fled to a nearby subway station and attempted to blend in with commuters. Aftonbladet's police source said the man took a northbound train toward Stockholm's international airport, then got on a southbound train in an apparent attempt to confuse authorities.
"He had nowhere to go," the source told Aftonbladet. "He behaved oddly."
The suspect is expected to appear before a judge on Saturday. Prosecutors have until Tuesday to decide whether to request the suspect be held or released.
The truck crash appeared to be the latest attack in Europe using a vehicle.
In an attack last month claimed by ISIS, a man drove into a crowd on London's Westminster Bridge, killing three people and injuring many others before stabbing a policeman to death. He was shot and killed by police. A fourth person, a woman thrown into the Thames by the force of the car attack, died Thursday.
The ISIS group also claimed responsibility for a truck attack that killed 86 people in Nice, France, in July 2016 during a Bastille Day festival, as well as another truck attack that killed 12 people at a Christmas market in Berlin.
In February, U.S. President Donald Trump suggested that Sweden could be the next European country to suffer the kind of extremist attacks that have devastated France, Belgium and Germany. Two days after his remarks, a riot broke out in predominantly immigrant suburb of Stockholm where police opened fire on rioters, a surprise to many Swedes who aren't used to officers using guns.
Friday's truck crash was near the site of a December 2010 attack in Stockholm in which Taimour Abdulwahab, a Swedish citizen who lived in Britain, detonated a suicide bomb, killing himself and injuring two others.
Abdulwahab had rigged a car with explosives in the hope the blast would drive people to Drottninggatan — the street hit Friday — where he would set off devices strapped to his chest and back. The car bomb never went off, and Abdulwahab died when one of his devices exploded among panicked Christmas shoppers.
The Associated Press contributed to this report.