Sweden has raised its threat level to "high" as the country's security services launched a manhunt for a man suspected of planning a terrorist attack. Denmark and Norway have also raised their threat levels.
Acting on "concrete information" Swedish authorities issued an arrest warrant for an unidentified man on Wednesday, and raised the threat level to four on a five point scale.
The head of domestic intelligence and counter-terrorism Anders Thornberg told a press conference there were no known ties between the individual who is the target of the manhunt and the Paris attacks.
However, Sweden's Sapo intelligence agency said the attacks in Paris last week "show that IS may have an increased ability to carry out even relatively complex attacks in Europe. Individuals may be inspired by these attacks. "
The new threat level determined by the National Center for Terrorist Threat Assessment (NCT) means there is a high probability "persons have the intent and ability to carry out an attack."
The assessment comes as authorities in Europe are on high alert as they continue to search for those tied to the Paris attacks and crack down on "Islamic State" cells.
Swedish police have raised their presence in public places, strategic locations and foreign embassies.
NCT director Mats Sandberg said at the press conference IS "considers Sweden a legitimate target."
While neutral, Sweden has participated in NATO missions in Afghanistan and is currently training Iraqi Kurdish peshmerga battling IS in northern Iraq.
Thornberg refrained from confirming an earlier Swedish media report that the suspect is an Iraqi who has fought in Syria and entered the country on Wednesday. "We don't want to disclose our methods," Thornberg said.
Denmark and Norway also raised their threat levels to the second highest level on Wednesday, citing security concerns following the terror attacks in Paris.
Sweden for years has had a large Iraqi Kurdish and Arab diaspora population. The country has recently been forced to impose border controls after being overwhelmed by refugees fleeing conflict in Syria and Iraq.