A leaflet issued by the British Association of Chief Police Officers provides information and advice for those who may be thinking of traveling to Syria. (Leon Neal/AFP/Getty Images)

British counter­terrorism officials made a direct appeal Thursday to mothers, wives, sisters and girlfriends as they urged British women to persuade loved ones not to travel to Syria to take part in that country’s bloody civil war.

Authorities across Europe are increasingly concerned about the number of would-be jihadists traveling to Syria to fight against President Bashar al-Assad’s government. On Wednesday, French authorities announced measures that they hope will curb the numbers of young people boarding flights to Syria, such as urging suspicious parents to inform police about their children’s plans.

In Britain, police chiefs are focusing on female family members because “women are strong influences in families, they are able to identify changes in behaviour and they are often willing to seek help for their families,” Helen Ball, senior national counterterrorism coordinator, said in a public Web chat about the plan.

In a statement earlier in the day, Ball said the campaign was “not about criminalising people it is about preventing tragedies.”

Critics of the initiative question whether women would necessarily be willing to tip off authorities about their loved ones’ activities.

Keith Vaz, chair of the Home Affairs Select Committee in Parliament, told the BBC that London’s Metropolitan Police were “not a counseling service — they are the first stage in the criminal enforcement process — and families may be very reluctant to do this.”

As part of the campaign, police also urged those wishing to assist with the humanitarian crisis in Syria to consider donating to charities rather than traveling to the war-torn country.

As many as 400 British Muslims are thought to have headed to Syria since the conflict began in 2011. Authorities are concerned that some may return radicalized, leading to violence at home.

British police say the number of Syria-related arrests has jumped in 2014, with 40 in the first three months of the year, compared with 25 in all of 2013.