A man who stabbed two American tourists at Amsterdam’s central station has told a court he wanted to avenge far-right politician Geert Wilders’s decision to hold a competition for cartoons depicting the prophet Muhammad.

Jawed S. travelled by train from his home in Germany to Amsterdam where he attacked two people standing by an information desk before he was overpowered by police.

S., a 20-year-old Afghan refugee who had been granted permission to stay in Germany, appeared in a high-security courtroom in Amsterdam on Monday charged with two counts of murder with terrorist intent.

While S. refused to name Wilders in person, he made clear that the contest was the motive for his journey. ‘Why did you give that dirty pig the opportunity to insult our prophet?’ he said. ‘I came to the Netherlands to defend my prophet. I wanted to kill dishonest and cruel people.’

Wilders had cancelled the competition the previous day following several days of violent protest in Pakistan, inspired by the hardline Islamic party TLP. Foreign affairs minister Stef Blok made plain he disapproved of the contest but said banning it would violate freedom of expression.

In previous hearings S. said he had no regrets about his actions and was prepared to die ‘a martyr’, but on Monday he added: ‘If I’d known they were tourists I wouldn’t have touched them.’

The victims are due to give evidence to the court on Tuesday, after which the prosecution will submit its sentencing demands.