Swedish police said Monday they suspected arson in connection with an overnight fire that damaged a Shiite mosque near the capital, Stockholm.
The Imam Ali Islamic Centre in Jarfalla, a municipality north-west of Stockholm, said in a post on Facebook that about one-fourth of the building was destroyed.
No one was injured in the blaze that appeared to have started on one of the outer walls, according to police who have opened an investigation into arson.
Fire fighters were quickly at the scene after the alert was sounded late Sunday.
Earlier in the evening, several hundred people had attended a gathering in the building.
"We are very disappointed. This is the largest Shiite Muslim mosque in Sweden with thousands of members," spokesman Akil Zahiri told Swedish broadcaster SVT.
He expressed shock and sorrow over the incident, and said many members of the congregation were worried.
"If the police conclude it was arson, it is key that we step up security measures but we will wait for their findings," Zahiri said.
The mosque had previously installed security cameras.
Zahiri declined to comment if the mosque had been subjected to recent threats.
The centre also houses a library as well as youth and culture associations. The centre said it had cancelled all planned activities until Thursday.
The association that runs the mosque was formed in 1997.