Updated at 3:15 p.m. ETAuthorities in Sweden say they have made one arrest after a truck drove into pedestrians on a major shopping and tourist street in Stockholm Friday, causing multiple injuries and fatalities.The vehicle, a stolen beer delivery truck, plowed through the pedestrian street and crashed into an upscale department store. Four people died and 15 were injured, according to police.Authorities say they are investigating the incident as a possible terror attack.Earlier on Friday, police questioned two people who they did not identify as suspects. (At one point Sweden's prime minister said someone had been arrested, but police said that was not true.)Then authorities released a photo of a man they said was wanted in connection with the crash."The picture shows a man clad in a hooded jacket on an escalator in what appears to be the Stockholm metro," Radio Sweden reported. "The police stressed he is not suspected of the deed, but is wanted for questioning."Swedish police have now arrested that man, but would not identify who he is or why he was wanted. He "may have connections" to the attack, police said, but provided no details.Swedish Prime Minister Stefan Löfven, speaking shortly after the incident, said there were indications the truck hit pedestrians as "a terror attack." But Radio Sweden reports that the Swedish Security Service says there is no confirmation the incident was an act of terrorism.Police were unable to confirm early reports of gunfire at the scene.The incident occurred on Drottninggatan, or Queen Street, a popular walking destination lined with shops. The location of the crash was a pedestrian-only section of the street, according to Radio Sweden."It's a very crowded part of the city," Swedish journalist Lava Delo told NPR's Morning Edition.Video footage shows people fleeing.The Local, an English-language news agency with reporters in Sweden, reports that a brewery says the truck was hijacked from one of its staff members: