Police officers stand guard on a street after an attack in central Stockholm, capital of Sweden, on April 7, 2017. (Xinhua/Rob Schoenbaum)

STOCKHOLM, April 8 (Xinhua) -- Explosives were found in the truck used in Friday's attack in Stockholm, which killed four people and injured 15 others, Swedish Television (SVT) reported quoting police sources on Saturday.

Police have arrested a man from Uzebekistan, suspecting him of being the driver of the truck that rammed into people on a central Stockholm street on Friday.

SVT quoted the sources saying a homemade bomb placed in a bag was found in the truck, suspecting that it failed to be detonated during the attack.

Death toll of Stockholm attack rises to four, after one victim died in hospital. Swedish Television quoted hospital sources at Karolinska institute as saying that the number of the injured from the attack had risen to 15.