Pakistani police raided offices and homes of dozens of radical Islamic leaders, putting several under house arrest and detaining hundreds of their associates in a bid to foil a Sunday rally in the capital to protest cartoons of the Prophet Muhammad, officials said. But Maulana Fazlur Rahman, a lawmaker and parliamentary opposition leader from the six-party religious coalition that is organizing the rally, vowed it would proceed despite a government ban and police barricades around the capital. Qazi Hussain Ahmad, the chief of the six-party coalition, was placed under house arrest in the eastern city of Lahore, while other senior leaders in Islamabad were either arrested or asked not to leave their homes. Mian Maqsood, a spokesman for the coalition, said "hundreds" of Islamic leaders had been arrested, although Interior Minister Aftab Khan Sherpao said only about two dozen had been detained to stop the latest protest against the publication of Prophet Muhammad cartoons in Europe and elsewhere. Chaudhry Shafqaat Ahmed, chief investigator of Lahore police, said about 150 supporters of the coalition and several other religious groups were arrested Saturday night and another 150 were listed to be arrested. The arrests came hours after the government warned radical Islamic groups against holding the rally, fearing it would spark more violence after at least five people died in riots across the country over the past week. Police had set up road blocks into Islamabad Sunday and cars and other vehicles were being checked for supporters of the religious alliance. Paramilitary troops patrolled the streets in pickup trucks with mounted machine guns, while soldiers barricaded themselves behind sand bags near key government buildings and at an enclave housing foreign embassies, witnesses said.