Four men have been sentenced to six years in jail in absentia for joining Islamic terror groups in Syria and Iraq and planning to carry out terrorist attacks.

Noureddin B, Abdullah R and Thijs B are thought to be in Syria or Iraq and Driss D is thought to be dead. No lawyers representing them were in court to hear the sentence, the Telegraaf reported.

The four all left the Netherlands in 2012 or 2013 after coming into contact with extreme Muslim ideologies, the court had been told. Three of the four had a criminal record.

The trial was part of the public prosecution service’s Context operation in which a number of alleged Dutch jihadis are being prosecuted. Last December eight men and one woman were sentenced to six years in jail and one case was suspended because the suspect had died.

Operation Context was launched in 2013 when parents reported that their children had gone to Syria to join jihadi forces after being recruited by radicals in the Netherlands.

The case against three others, who do have legal representation, is ongoing, the Telegraaf said.