Serious weaknesses in Europe's attempts to identify indigenous Islamic radicals have been exposed by last week's murder of Dutch filmmaker Theo van Gogh, according to counter-terrorism experts who see the killing as a new development of the global terrorist threat.

Their worries were highlighted by a report given to the Netherlands parliament yesterday. It showed that Dutch security services have been trailing a Netherlands-based international network of Islamic radicals - called the "Hofstadnetwerk" - since the summer of 2002.