RNA - Police spokesman, Lars Bystrom, said on Monday that Imam Ali Islamic Center in the northern Stockholm suburb of Jakobsberg was badly damaged in the arson attack overnight.
"It seems it was set ablaze from the outside," the TT news agency quoted the spokesman as saying, noting, "Flames were engulfing the outer facade" of the mosque.
Mosque spokesman, Akil Zahari, told the Swedish national public TV broadcaster, SVT, that the center was attended by thousands of faithful worshipers every day.
Several mosques in Sweden have been the target of arson attacks in recent years. Only a few perpetrators have been caught over the attacks.
In April last year, a 31-year-old man was jailed for three years for racially-aggravated arson after admitting to setting fire to a mosque in the southwestern town of Boras.
In January 2015, Swedish anti-racism campaigners protested after a trio of arson attacks on mosques in the Nordic country.
This comes as anti-Islam attacks are on the rise across the US and several European countries. Figures show attacks against mosques and property owned by Muslims have increased sharply in the Western countries.
France and some other European countries have shut down dozens of mosques and prayer halls in recent months.
Several European countries have recently seen the rise of far-right groups opposing the entry of refugees, most of whom are fleeing conflict zones in Africa and the Middle East, particularly Syria.
This as many blame major European powers for the unprecedented exodus, saying their policies have led to a surge in terrorism and war in the violence-hit regions, forcing more people out of their homes. They also cite the support by some Western countries for militants operating in the Middle East as the main reason behind the departure of refugees from their home countries.
The refugee crisis in Europe and a series of Daesh-related terrorist attacks have led to the rise of Islamophobia among racists and xenophobes in the West.
Some observers say the recent rise of US President Donald Trump has coincided with the rise of anti-Muslim hate among groups across Europe as well.
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