El-Tawheed mosque could only be in Amsterdam. Across the street is a coffee shop serving soft drugs. The facade of a house a few doors down is painted with naked female figures. And while some women passing the mosque wear veils, others cycle by in T-shirts.

El-Tawheed mosque became notorious in 2004 when Mohammed Bouyeri, a young man who had prayed there, murdered the Dutch filmmaker Theo van Gogh. Mr Bouyeri’s friend Samir Azzouz, now serving eight years in jail for planning terrorist attacks, also prayed at El-Tawheed.