Flags flew at half-staff across the Swedish capital Saturday as police sought further details about a 39-year-old Uzbek national suspected of ramming a stolen truck into an upscale shopping hub, killing four people and wounding 15 others.
The suspected terrorist was previously known to Swedish intelligence services, but authorities said he was not a part of any ongoing investigations.
"Nothing indicates we have the wrong person," Dan Eliasson, head of Sweden's national police, told reporters Saturday. "On the contrary, suspicions have strengthened as the investigation has progressed."
Eliasson also said investigators still did not know whether others were involved in Friday's attack.
"We cannot exclude this," he said, while noting "clear similarities" to a March 22 truck attack in London that killed two civilians and a police officer near Parliament and wounded 40 others. But unlike the London attack, which was claimed by Islamic State extremists, there was no such claim for the Stockholm killings.
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 said the truck went 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.
Following the attack, Stockholm's central train station was evacuated and nearby buildings were locked down for hours. Police said they had increased security at the country’s borders.
Sweden's King Carl Gustaf expressed his condolences for the victims and their families in a brief statement.
"We follow developments but as of now our thoughts go to the victims and their families,'' he said. The king cut short a visit to Brazil on Friday to return home.
A number of European leaders, including German Chancellor Angela Merkel and London Mayor Saddiq Khan, released statements indicating their solidarity with Sweden.
"One of Europe's most vibrant and colorful cities appears to have been struck by those wishing it — and our very way of life — harm," said European Commission President Jean-Claude Juncker. "An attack on any of our [European Union] member states is an attack on us all."
French President Francois Hollande voiced his "horror and indignation" over the assault. Paris’ Eiffel Tower went dark for five minutes Friday to honor the victims of the attack.
In neighboring Finland, President Sauli Niinisto called the attack a “maniac act of terror,” while Danish Prime Minister Lars Loekke Rasmussen said it was a cowardly attempt “to subdue us and the peaceful way we live in Scandinavia.”
The U.S. State Department also condemned the attack, adding, “Attacks like this are intended to sow the seeds of fear, but in fact they only strengthen our shared resolve to combat terrorism around the world.”