"To avoid the risk of victims of Islamic violence, I have decided not to let the cartoon contest go ahead," far-right opposition politician Geert Wilders said in a written statement.

Wilders, who for years has lived under round-the-clock protection because of death threats sparked by his fierce anti-Islam rhetoric, said he does not want others endangered by the contest he planned for November.

The planned contest sparked angry protests in Pakistan and a death threat this week from a 26-year-old man, reportedly a Pakistani, who was arrested Tuesday in The Hague.

Physical depictions of the prophet are forbidden in Islam and deeply offensive to Muslims.

"It's not just about me," Wilders said in the statement. Strong opponents of the event "see not only me, but the entire Netherlands as a target."

The contest was to have been held at the tightly guarded offices of his Party for Freedom in the Dutch parliament building.

Earlier Thursday, a Dutch judge extended by two weeks the detention of the man who allegedly threatened to attack Wilders.

Prosecutors said in a statement that an investigating judge ordered the suspect held while he is investigated on charges of making a terrorist threat, making preparations for a terrorist murder and incitement.

The Dutch government had been at pains to distance itself from the contest.

Prime Minister Mark Rutte last week questioned Wilders' motive for organizing the contest.

"His aim is not to have a debate about Islam. His aim is to be provocative," the prime minister said.

However, Rutte added that people in the Netherlands have far-reaching freedom of speech rights and the government did not intend to seek the contest's cancellation.

In a clear indication of the anger Wilders had generated, thousands of hard-line Islamists marched toward Pakistan's capital Thursday in protest.

Some 10,000 supporters of the Tehreek-i-Labaik group, which helped Imran Khan to become prime minister following last month's national elections, set out on the march Wednesday, calling on Khan to cut diplomatic ties with the Netherlands.