The new victims have come forward following the death of Valerii Ranert close to Dublin Airport last Monday.

He was pulled out of his car and given a vicious beating while his girlfriend looked on.

A gang of three men from nearby Coolock are suspected of carrying out the attack and they were arrested before being released without charge.

Ranert had parked his Volkswagen Golf in a lay-by at the Naul Road in Swords when he was targeted by the men. The 28 year-old's Estonian girlfriend was with him in the car in the area which is popular with courting couples.

The gang demanded his mobile phone but Ranert refused. The men then kicked in the glass of the driver's door before pulling him out and repeatedly kicked him in the head.

When they realised that the victim was seriously injured they stole his car and subsequently set it alight at a halting site in Coolock. They suspects, who are aged between 17 and 23, live nearby.

Gardai suspect the men have been behind a spate of thefts in the Coolock and Darndale areas over the last 18 months. All three have previous convictions.

Detectives have built up a detailed picture of how they operate. The men drive to lay-bys at the Naul Road and Collinstown and approach couples in cars asking to borrow a mobile phone.

Most people refuse but the men then issue threats and in the past have forcibly stolen several mobile phones.

Eight previous victims have come forward and officers believe that far more people have been targeted and have appealed for witnesses to contact them.

One incident occurred at 6.15pm but most happened in the early hours of the morning and one goes back over 12 months. None of the victims originally reported their experiences to gardai.

It is not thought that the gang intended to kill Ranert but got angry when he refused to hand over his phone. Gardai believe the men did not use a weapon but instead attacked the victim with their heavy boots.

Ranert's girlfriend managed to raise the alarm but he was pronounced dead in hospital a short time after the attack.

The woman, who is 28 and worked as a cleaner, is said to be devastated over her boyfriend's death. She returned to Estonia on Thursday night and has vowed never to come back to Ireland.

Ranert had lived here for two years and worked as a forklift driver in Blanchardstown in west Dublin.

He had a five-year-old daughter in Estonia from a previous marriage and returned home to visit her for a week every three months.