A Labour MP has warned that as many as 1,500 young British people may have been recruited by extremists to fight in Syria and Iraq.
Khalid Mahmood, the MP for Birmingham Perry Barr, said the number of Brits fighting in the region could be much higher than the government estimates.
The UK's counter-terrorism chief for the Association of Chief Police Officers has previously told ITV News that estimated 500 British people are currently fighting in Syria, but admitted the number could be far higher.
Leaders of a Cardiff mosque, attended by 3 young men who are now fighting in Syria, say they had nothing to do with their radicalisation.
The Home Secretary has told ITV News that young women have left Britain to fight for the extremists group ISIS in Syria and Iraq.