So far at least 12 people from The Hague have died taking part in jihad in Syria and Iraq, new city council figures show.

Mayor Jozias van Aaartsen will not say how they died but did confirm they are ‘mainly’ young men, the Telegraaf reports. So far 40 young men and six women have left The Hague for Syria and Iraq and three children have been stopped from going, the paper says.

In the meantime, 11 people have returned. Van Aartsen declined to say why they had come back – because they are injured, out of nostalgia or other motives. Around 20 The Hague jihadis are still in the region.

The figures were published on Tuesday at the presentation of a plan to try to stop youngsters becoming jihadis. In particular, the city wants to do more to identify ‘potentially violent individuals’.

One option would be to recruit hundreds of ‘key figures’ to listen to radicalised youngsters. ‘We have to make it clear to them that they might be going to god’s country but they will end up in a terrible situation,’ the Telegraaf quotes the mayor as saying.

The city is also preparing to help returnees reintegrate into society. ‘You have to ensure a 14-year-old girl can go back to school,’ Van Aartsen said. ‘And that is not easy. If someone has committed crimes, they must face the courts. And people who are traumatised need psychiatric help.’