The site of a violent attack is blocked by the police in Stockholm, Sweden, April 8, 2017. (Xinhua/Shi Tiansheng)

STOCKHOLM, April 9 (Xinhua) -- One more person has been arrested in relation to Friday's Stockholm attack, Swedish TT News Agency reported on Sunday.

Swedish Television reported that the arrest on Sunday was a result of the preliminary investigation that raised suspicions against the person.

Two men had been arrested earlier on suspicion of involvement in the attack.

Swedish police have identified one of the previously arrested men in the north of Stockholm as a 39-year-old man from Uzbekistan, who had expressed support for the Islamic State (IS) online and was known to intelligence agencies, according to Swedish paper Aftonbladet.

Police believed this man was the one driving the truck on Friday, the report said, quoting police source as saying that "the evidence looks very strong" that the Uzbek man was the driver of the hijacked truck.

Police said that "there is nothing concrete to suggest further attacks", SVT reported.

Meanwhile, the police confirmed Sunday that two Swedes, one Briton and one Belgian were killed in attack.

A truck rammed into people on a central Stockholm street before crashing into a department store on Friday, killing four and wounding 15 others.

SVT reported that ten people are still hospitalized and four of them are in serious condition.