Smoke billows from the windows of a mosque in Eskilstuna
Smoke billows from the windows of a mosque in EskilstunaReuters

For the third time in a week, a mosque in Sweden was torched on Thursday, causing Swedish police to launch a manhunt for the culprit.

"People saw a man throwing something burning at the building," police in Uppsala, where the latest arson took place, said in a statement quoted by AFP. They added that the mosque in eastern Sweden did not catch fire and that the suspect had left behind "a text on the door expressing contempt for religion."

A police spokesman told Swedish news agency TT that the burning object was a Molotov cocktail and that no one was in the building at the time.

Sweden's Islamic Association posted a photograph online of the main door of the mosque, which was emblazoned with the slogan "Go home Muslim s**t".

"The crime has been classed as attempted arson, vandalism and incitement to hatred," the police said, appealing for witnesses to come forward.

Thursday's attack in Sweden's fourth-largest city came just three days after a late-night blaze at a mosque in Esloev in the south, which police suspect was also arson.

Last week, on Christmas Day, five people were injured when a petrol bomb was thrown through the window of a mosque in Eskilstuna, east of the capital Stockholm.

Sweden's leftist Prime Minister Stefan Loefven led condemnation of the latest attack.

"The most important thing now is that everyone distances themselves from this," he told TT.

"In Sweden no one should have to be afraid when they practice their religion," he added, saying the government would increase funding for securing places of worship.

The attacks come as debate intensifies in Sweden over immigration and the integration of asylum seekers in the traditionally tolerant Nordic country, which is expected to receive more than 100,000 asylum applications this year, breaking all previous records.

On December 3, the Sweden Democrats - a populist party with a strongly anti-immigration agenda - brought down the minority governing coalition after it had been in power for just two-and-a-half months, by refusing to support its budget plans.

However in a last minute agreement on December 27, the government and center right opposition parties cut a deal effectively denying the Sweden Democrats influence over major policy -- including over immigration.

Muslim groups have called on politicians to join vigils in several cities around the country Friday to show their opposition to racially-motivated violence, reported AFP.