Police received a call at 1.20am and arrived together with emergency workers to find one man dead from gunshot injuries and a group of people who had witnessed the killing gathered outside the restaurant.
Testimony from witnesses provided police with enough evidence to issue an arrest warrant for the suspected killer, police spokesperson Fredrik Ladenstedt told the TT news agency Thursday morning.
“The witnesses have been questioned overnight and it appears that it stems from some prior history between the men,” he said.
However Ladenstedt refused to go into greater detail regarding what sort of rivalry the two men have had or what relationship they had with one another.
Both the man suspected of murder and the victim are in their thirties and reside in the Upplands Väsby area.
On Thursday morning, police continued to search for the suspect in the Stockholm area.