Swedish police say they can not say how many people were killed or injured when a truck ran into a crowd in downtown Stockholm, and they have not found the driver.
"Sweden has been attacked", he told reporters.
Live television footage showed smoke coming out of the upscale Ahlens department store on Drottninggatan Street, which the truck smashed into. But all trains to and from Stockholm's central station were cancelled for the day.
On Thursday, an Israeli soldier was killed and another injured in a vehicular attack, which has become a common means of terror attacks in Israel since an uptick in violence began in October 2015.
Chancellor Angela Merkel's spokesman says the German government's "thoughts are with the people in Stockholm, the injured, the relatives, first responders and police" after a truck crashed into a department store, killing several people.
Swedish beer maker Spendrups said one of its trucks had been hijacked earlier Friday. He was shot dead by police.
There was no immediate claim of responsibility for Friday's attack, but vehicles have been common weapons in recent extremist attacks.
World leaders and European politicians reacted with solidarity to the news of the attack, with European Commission President Jean-Claude Juncker saying that it was an "attack on us all".
Officials on the ground say three people have been killed with many injured.
Friday's crash is 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.
Local health authorities said that one person died in hospital and 15 others, including children, are injured. Swedish radio says Friday that three people have been killed in the crash and Swedish broadcaster SVT says shots have been fired.
They released a picture that was taken near the scene of the carnage Friday and urged people to call the police if they spotted the man. Eyewitnesses reported it being driven at speed along Drottninggatan (Queen Street) before it crashed into the front of a department store.
No group has yet claimed responsibility for the incident outside the well-known Ahlens department store, on a busy shopping street.
"We stood inside a shoe store and heard something. and then people started to scream", witness Jan Granroth told the Aftonbladet daily.
Security services said the driver of the truck was not in custody and a manhunt was underway.
"During a delivery to (a) restaurant, and while the driver was unloading, someone jumped into the driver's seat and drove off with it", Spendrups communications director Marten Lyth told TT Swedish news agency. Police spokeswoman Towe Hagg says people have been injured but she would not confirm the deaths.
A large area of central Stockholm has been cordoned off and evacuated by police, with Sweden's parliament evacuated as a precaution and public transport in the capital shut down.
Putin says US strikes on Syria illegal, harm US-Russia ties
The Turkish health ministry on Thursday said initial analysis suggested victims were exposed to the deadly nerve agent sarin. The attack marks the USA response to the alleged chemical attack on rebel-held town in northwestern Syria last Tuesday.