Parents of young militants heading to the Middle East to fight for the Islamic State of Iraq and Syria ( ISIS ) and other extremist groups are imploring them to return home.

In one July YouTube post, three Moroccan mothers cry, saying that their children left them with nothing and no one to care for them – in order to die for someone else's cause.

The parents of Aqsa Mahmood 19, who last November travelled from Scotland to Syria to join ISIS , in September again called on their daughter to hurry home, CNN reported.

Looking directly into the camera, Aqsa's mother Khalida says, "Aqsa, my dear daughter, please come back. At this moment, I am missing you a lot. Your sisters and brother miss you a lot. My dear daughter, in the name of God, I beg you to come back. I miss you a lot. I love you. I love you, my dear daughter. Please come back."

In a video posted in February 2013, parents of 16-year-old Tunisian Rahma, who travelled to Syria for "jihad", tearfully call for their daughter to come home.

In July, the fathers of two best friends from Belgium went to northern Syria to persuade their sons to leave ISIS, the BBC reported.

Pol Van Hessche and Idriss Boutalliss made a dangerous three-day journey across the desert to see their sons, but their boys refused to quit, the BBC said.

"Her immense grief and apprehension"

Because foreign fighters use Twitter to communicate with the outside world and spread their news, many parents are also sending messages via Twitter or posting video messages on YouTube, Cairo University media professor Hassan Afifi said.

"The repeated appeals by parents to their sons who fight alongside ISIS … have a significant impact not only on the sons – for whom the messages are intended – but also on youth who are still in their home countries and may be considering joining terrorist organisations," Hassan said.

These appeals are very effective in countering ISIS and "its propaganda, which drives recruitment and makes extensive use of websites, modern means of communication and social networking sites", he added.

The words of parents can greatly influence sons or daughters who've gone to Syria or Iraq to fight alongside terrorist groups, said Enas al-Jamal, a child psychologist and lecturer at Ain Shams University in Cairo.

The things that entice youth to travel abroad – "the false religious propaganda , the incitement to fighting and the thrill of a new environment" – begin to wear off after some time, she said.

"Any counteractive factor, such as mothers' messages, will be well received by their sons who are leaving for jihad, for the words a mother writes on Twitter, or the video clips she posts on YouTube, which express her immense grief and apprehension about the fate of her son, will find their way into the sons' hearts," Enas said.