Swedish police were hunting Wednesday for a man wanted for "planning a terrorist act", security services said, with the country on high alert following the deadly terror assault in Paris last week.

Swedish police were hunting Wednesday for a man wanted for "planning a terrorist act", security services said, with the country on high alert following the deadly terror assault in Paris last week.

An arrest warrant has been issued for the suspect, whose identity has not been revealed, the head of domestic intelligence and counter-terrorism Anders Thornberg told a press conference in Stockholm.

"The man is being actively searched for," Thornberg said, refusing to confirm media reports the suspect is an Iraqi who has fought in Syria.

The suspect is wanted over his activities in Sweden and there is so far no link to the bloody attacks in Paris on Friday which left 129 people dead, according to Swedish intelligence service Sapo.

Sweden on Wednesday raised its national terror threat status to "high", the second-highest level on a five-point scale, following an assessment by the National Centre for Terrorist Threat Assessment (NCT).

Sapo said in a statement the move was done in response to "concrete information".

"The attacks in Paris on November 13 show that ISIL may have an increased ability to carry out even relatively complex attacks in Europe. Individuals may be inspired by these attacks," Sapo said.

NCT director Mats Sandberg told the news conference that the ISIL group -- which has claimed the Paris attacks -- "considers Sweden a legitimate target".

160 people were killed on November 14 when a terrorist group stormed a Paris theatre following two blasts near Stade de France.