The trial of an Irish citizen who has been detained in Egypt for almost four years has been delayed as a number of witnesses failed to turn up in court today.

Ibrahim Halawa, who is 21 and from Firhouse in Dublin, was arrested in Cairo in August 2013 during protests against the ousting of then president Mohammad Mursi.

This is the 24th time Mr Halawa has been in court.

The next hearing in the case has been scheduled for 4 July. 

His case involves more than 400 other defendants.

Following today's hearing, Minister for Foreign Affairs Charlie Flanagan said he was "disappointed" that the witnesses did not turn up to court.

He added that the presiding judge has taken steps to speed up the trial process. Mr Flanagan said lawyers have submitted a list of 18 priority witnesses today who will be called for the next hearing with no further witnesses being called on.

Mr Flanagan said that the 4 July date for the next hearing takes account of the practice in Egypt where courts do not convene during Ramadan.

He said that the Government "is continuing to give the highest priority attention to this consular case."

He added that PresidentAbdel el-Sisi has indicated that he will exercise his presidential powers to return Mr Halawa to Ireland following a verdict.

Amnesty International criticised the process saying Egypt "continues to ignore its obligations under both Egyptian and international human rights law."

Amnesty International held a demonstration outside the Egyptian embassy to highlight Mr Halawa's case and called on the Egyptian authorities to drop all charges against him and order his immediate and unconditional release.