It is part of a fresh drive to prevent more Britons being lured abroad by extremists.
Officers have spoken of the effect on relatives of people who make the journey in a new film titled Left Behind.
Hundreds of individuals have left the UK to go to Syria, including a number suspected of joining Islamic State. They include a number of people from Yorkshire.
As well as those intent on fighting, schoolgirls and young families are also among those feared to have made the trip to the war-ravaged country.
The video features accounts from a number of Prevent contact officers. Their role is to support the partners, parents and siblings of people who have “given up everything” to go to conflict zones.
One officer says: “One particular case, the son had gone to Syria and the younger child ... keeps on going to the bedroom trying to find his older brother.
“When he finds an empty bed he comes back downstairs. He obviously can’t understand what’s going on.”
The film describes the “devastation” of relatives.
It is an “emotional” role, another officer says, while a third adds: “It’s very difficult to explain to the mother she will never get to see her child’s coffin because her son has been killed on a field in Syria.”
The film, which was released this morning, also features a direct message to anyone who might know someone looking to travel to a conflict zone such as Syria.
“Speak to the police as soon as possible, the sooner the better. Do it before it’s too late,” an officer says.
Forces across the region are supporting the launch of the film, with one event being held at the One Community Centre in Lincoln Green, Leeds.
Regional police Prevent co-ordinator Detective Superintendent Nik Adams said: “Today’s event is just one example of communities working together to combat the very real issue of families who experience heartbreak when their loved ones travel abroad to an area of conflict.
“Prevent Contact Officers provide much needed support to the families affected and through their eyes, Left Behind gives a powerful insight into what is all too often a very distressing situation.
“Anyone who is worried about a loved one who might be thinking of travelling to a conflict zone should call police on 101. They can talk in confidence about their concerns and officers will work with families and specialist agencies to offer tailored support on a case-by-case basis.”
“I would like to take this opportunity to emphasise how important it is that families contact us with their concerns at an early stage, so that we can try to prevent their loved ones from being hurt or criminalised wherever possible. Alternatively, there are other people who are trained and able to provide practical help and advice. This includes healthcare professionals, social workers, teachers and local authorities.”
“Please raise your concerns early and help us to prevent unnecessary tragedies”
The video is the latest production from the Prevent Tragedies campaign – a joint initiative between police, partner agencies and community groups.
Deputy Assistant Commissioner Helen Ball, senior national co-ordinator for counter-terrorism policing, said: “For every individual who decides they want to travel, there is a wider family whose lives will be devastated as a result.
“This film shows that, at a time when officers are working to establish the facts, they are also seeing mothers, fathers, brothers and sisters coming to terms with the possible loss of a loved one.
“It is shattering for all concerned.”
New figures showed that in the year to the end of May, 84 people believed to have travelled to Syria were reported missing by their families, including 49 aged under 21.
The total was a fall compared with the previous year, when there were just over 100.
People who have travelled to Syria from Yorkshire included Dewsbury teenager Talha Asmal, 17, who became the youngest known suicide bomber. His family said he was groomed online. A Bradford woman also fled to Syria with her sisters and their children.
The news comes as it is claimed too many further education colleges and skills providers are leaving students at risk of radicalisation and extremism, according to Ofsted.
A “worrying” number of institutions are struggling to put in place a new government requirement to prevent people being drawn into terrorism, despite the majority of providers inspecting doing it well, the education watchdog said.