A man who stabbed three people in The Hague before being shot by police is refusing to let investigators examine his mobile phone as they try to establish a motive for the attacks.

Malek F. made his first appearance in court on Monday morning at the high-security compound at Schiphol airport. Prosecutors said they had not ruled out a terrorist motive because F., from Syria, shouted ‘Allahu Akbar’ as he carried out the attacks on May 5.

The 31-year-old has had a history of disturbed mental health since he arrived in the Netherlands as a Palestinian refugee from Syria. In court prosecutors said he had denied being in a psychotic state at the time of the attack.

F. also wrote Facebook posts saying that ‘unbelievers should go to hell’ and ‘that he would like to see them suffer with Allah’s help, now and in the afterlife.’ Prosecutors said his behaviour changed markedly in December, when he started praying more often and altered his appearance.

F. sat calmly and attentively throughout Monday’s hearing, AD reported. His lawyer, Job Knoester, accused police during the hearing of using excessive force against his client. ‘There is no way they needed to fire three shots,’ he said.

The Telegraaf reported that he had been involved in an incident in February where he threw furniture and possessions out of the window of his flat in the centre of The Hague. His family have said they intend to file a complaint against healthcare institution Parnassia for failing to act on earlier signs that he was in poor mental health.

After the incident in February he was taken into secure accommodation but later allowed to return unaccompanied to his flat.

The court was also told that one of F.’s victims was struggling to retain the will to live, despite having two children. The three victims, a 21-year-old man from Zoetmeer and two residents of The Hague aged 41 and 35, were all treated in hospital for their injuries.