Stockholm, Aug 18 (IANS): Swedish Prime Minister Ulf Kristersson has said that the government had thwarted several terrorist attacks.

"We know that planned acts of terrorism have been hindered," Kristersson said at a press conference on Thursday, hours after the Swedish Secret Service's decision to raise the terrorist threat level from "elevated" to "high", Xinhua news agency reported.

Addressing the same press conference, Minister for Justice Gunnar Strommer said: "During spring, several people were arrested in Sweden and abroad suspected of having prepared attacks in Sweden."

Strommer did not comment further on these arrests, but Swedish Television (SVT) reported that there were at least two known cases.

In April, five men were arrested in coordinated dawn raids in three Swedish cities. Four of them were later detained on suspicion of planning attacks triggered by the burning of the Quran, SVT reported.

Also in April, two men suspected of planning an attack on a church in Sweden were arrested by police in Germany, SVT reported.

In one of the locations raided by German police, chemicals and fertilizers that can be used for manufacturing explosives were found, SVT said, citing German newspaper Die Welt.

Sweden and Denmark have been in the spotlight in recent weeks after several extremists repeatedly burned or desecrated the Quran in the two countries' capitals, sparking criticism from Muslim countries across the world.