Stockholm (AFP) - More than a thousand protesters took to the streets in Sweden on Friday to urge an end to a spate of attacks against mosques, amid growing tensions over the rise of an anti-immigration party.

The demonstrations in Sweden's three largest cities, Stockholm, Malmoe and Gothenburg, came a day after what was believed to be the third arson attack on a mosque in the space of a week.

"We want to send the message that these attacks on mosques... are a problem for all of society and not just Muslims," Mohammed Kharraki a spokesman for Sweden's Islamic Association told AFP from the largest demonstration in the capital Stockholm.

"This is about people being denied their basic rights.... Everyone needs to ask themselves, politicians and citizens if this is the kind of society they want."

Eyewitnesses saw a man throwing a petrol bomb at a mosque in Uppsala in eastern Sweden early on New Year's day, three days after a late-night blaze at a mosque in Esloev in the south, which police suspect was also arson.

The slogan "Go home Muslim shit" was also emblazoned across the doors of the building.

On Christmas Day, five people were injured in another suspected arson attack on a mosque in Eskilstuna, west of the capital Stockholm.

Swedish police said that they were stepping up security around mosques and continuing to search for the culprits.

"We are working flat out with the investigation but we have no leads to report yet," police spokeswoman Lisa Sannervik in Uppsala told AFP.

- Intimidation -

According to the anti-racism magazine Expo, there have been at least a dozen confirmed attacks on mosques in Sweden in the last year and a far larger number are believed to have gone unreported.

In a government survey of hate crimes in November two-thirds of Swedish Muslim associations said their buildings had been vandalised.

Sweden's Minister for Culture and Democracy Alice Bah Kuhnke said the latest attacks "aimed at intimidating and diminishing" people.

Story continues

"That's why one of the most important things we can do is to not let ourselves be intimidated," she told demonstrators in Stockholm, adding that the police would prioritise the search for the culprits and step up the protection of places of worship.

The mosque attacks come as debate intensifies in Sweden over immigration in the traditionally tolerant Nordic country, which is expected to receive about 100,000 asylum applications this year, a record.

Last month the far right Sweden Democrats -- which doubled their support to 13 percent in September elections -- came close to bringing down the left-green government over its liberal refugee policies.

The party, which wants to cut immigration by 90 percent, has increased its support in opinion polls to around 16 percent.