Police was called to the scene just before 5.30 in the morning. When they arrived they could see that there had been a fire but that it had died down. There was also offensive graffiti on the entrance doors to the premises. The police investigation is now into arson as well as incitement to racial hatred.
A spokesperson for Uppsala Police, Lisa Sannervik told Swedish Radio P4 that there are "a number of witnesses to the incident" and that the police have secured technical evidence from the scene.
This is the forth attack against a mosque in Sweden in a matter of days. Police in Eslöv in southern Sweden, are investigating arson, after the mosque there was put on fire on the 29th of December. In Eskilstuna, west of Stockholm, a mosque started burning on Christmas Day, as over 70 people, including children, were in the premises. Five people were taken to hospital. The day after, the tabloid Expressen reported that the window of another mosque in Eskilstuna was destroyed, and two cars, parked outside where damaged.
Lisa Sannervik, with the police in Uppsala said they were not aware of any specific threats issued against the mosque there.
"So far we do not know of any motive to why this has been done, but it is probably not a coincidence considering what has happened around the country," she told Swedish Radio P4.
In a report by the anti-racist organisation Expo, published on Wednesday, 2014 is called " a dark year for practicing muslims in Sweden". Data collected by the organisation shows that, on average, one mosque per month has been under attack. "The number of unrecorded cases is likely to be large" according to the report.
According to Simon Stjernholm, Ph.D in Islamology at Lund university, many of the attacks and threats against religious communities go unreported.
"Our picture is that muslims often hesitate to report it, perhaps the trust in the police is not there," he told the news agency TT.
In a report for the Swedish Commission for Government Support to Faith Communities, Stjernholm and the co-authors recommend that the religious communities inform their members of how to report a crime to the police, and that they stress the importance of doing so.
"We also recommend that the different faith communities work together on these issues," he said.