Media playback is unsupported on your device Media caption "Senior counter-terrorism detectives believe this issue won't go away quickly", reports Daniel Sandford

The two West Yorkshire teenagers feared to have travelled to Syria have been named.

The BBC has been told they are Hassan Munshi and Talha Asmal, both aged 17 and from Dewsbury.

Their families said they were praying for the safe return of the "ordinary Yorkshire lads".

The boys are thought to have flown from Manchester to Dalaman in Turkey on 31 March and are feared to be making their way to Syria to join Islamic State.

Hassan's brother Hammaad Munshi was arrested in 2006 at the age of 16 after police found a guide to making napalm on his computer.

Image caption Hassan's older brother Hammaad Munshi became the youngest person convicted under the Terrorism Act

He became the youngest person to be convicted under the Terrorism Act.

West Yorkshire Police has been supporting the families of the two missing boys, who have said they are in "a state of profound shock".

A statement released on behalf of the families said: "These were just two ordinary Yorkshire lads who enjoyed the things that all young people enjoy at their age.

"Both Hasan and Talha had a promising future as an apprentice and an A-level student respectively, and we are praying they will be back with us soon and are able to realise that future."

They urged parents to be "extra vigilant" although "it's near impossible to know your children have been groomed and brainwashed", the statement said.

Police officers are carrying out inquiries alongside the North East Counter Terrorism Unit.

Assistant Chief Constable Mark Milsom said police were "extremely concerned".

"Our priority is for their safe return. Their families are gravely worried about them and want them home," he said.

"Syria is an extremely dangerous place and the public will be aware of the dangers these boys may face.

"The choice of returning home from Syria is often taken away from those that come under the control of Islamic State, leaving their families in the UK devastated and with very few options to secure their safe return."

The boys were last seen by their families on the day they are believed to have boarded the Thomas Cook flight to Turkey, West Yorkshire Police said.

A spokesman for Thomas Cook Airlines said: "Whilst we cannot confirm the names of any of our passengers who travel with us, we can reassure all our customers that we work closely with all authorities to ensure the safety of our flights in and out of the UK."

Image caption Jawad Khan from Dewsbury said more must be done to integrate young British Muslims

Jawad Khan, a student from Savile Town in Dewsbury, said: "A lot of young Muslims don't feel part of this society. They feel like they don't fit in.

"I think we need to do a lot more to integrate them, to make sure they don't feel they have to change. They can be both Muslims and British - the two go together, they are not opposite."

Kirklees Council Chief Executive Adrian Lythgo added: "We are deeply concerned for these young people and will continue to work in close partnership with the Counter Terrorism Unit, West Yorkshire Police, our communities and schools to prevent and eradicate any threats and concerns."