Sweden held a moment of silence Monday for the victims of Friday's terrorist truck attack killed four people and injured 15.
A 39-year-old Uzbek believed to have extremist sympathies is under arrest for allegedly ramming a stolen truck into a crowd at the Ahlens department store in Stockholm.
On Sunday, tens of thousands of Swedes turned out in Stockholm for what they called a "lovefest" after the attack.
"Fear shall not reign. Terror cannot win," Mayor Karin Wanngard told a crowd estimated at 50,000.
One woman held a poster reading: "We don't respond with fear, we respond with love."
In Washington, the White House says President Donald Trump spoke by phone with Prime Minister Stefan Lofven of Sweden “to express condolences to the loved ones of those who were killed." A statement said the two leaders agreed to maintain their close partnership in the global fight against terrorism.
Police arrested the Uzbek-born suspect hours after the truck attack. He was known to intelligence services since last year when he disappeared before he could be deported after his application for asylum was rejected. Authorities knew he had pro-extremist sympathies.
But no group has claimed responsibility for Friday's attack and no motive is known.
Police say they have arrested a second person in connection with the attack, but have given no further information.
Photos taken at the scene Friday showed the vehicle was a truck belonging to beer maker Spendrups, which said its truck had been hijacked earlier in the day.
Witnesses say the truck drove straight into the entrance of the Ahlens Department Store on Drottninggatan, the city's biggest pedestrian street, sending shoppers screaming and running. Television footage showed smoke coming out of the store after the crash.