More than 25,000 people rallied Sunday in the largest protest in Pakistan so far against an anti-Koran film made by a Dutch lawmaker, urging their government to expel the Netherlands ambassador.

"They call this freedom of expression, but it's freedom of aggression," keynote speaker Munawwar Hasan, a leader of the main Islamic party Jamat-e-Islami, told the crowd as it chanted "God is great."

The 15-minute film by Geert Wilders, which sets verses from the Muslim holy book against a background of violent images from terror attacks, was released in March. It has sparked weekly protests in Pakistan, usually drawing hundreds of people after prayers on Friday, the Muslim holy day.

Click here for photos.

But police officer Syed Suleman estimated Sunday's crowd at 25,000, while organizers claimed more than 100,000 people turned out.

Wearing head bands inscribed "We are ready to sacrifice our lives for the sanctity of the prophet," they marched for two kilometers (more than a mile), then gathered on Karachi's main street to listen to speeches.

They also burned an effigy of Wilders as speakers said their government should sever diplomatic ties with Western countries supporting the publishers of cartoons defaming the Prophet Muhammad.

"The Muslim world is on one side, but Muslim rulers like (President Pervez) Musharraf are toeing the Western agenda under the garb of secularism," Hasan said, referring to Musharraf's role in Washington's war on terrorism.

Hasan said this rally, named "The glory of the prophet march," was not against the West in general, but was aimed at creating awareness among Muslims that they need to unite against a war against Islam.