About 25,000 people rallied peacefully against the Prophet Muhammad cartoons in Pakistan's largest city Sunday while police prevented an illegal rally in the eastern city of Lahore by arresting scores of would-be protesters. Pakistan banned anti-cartoon rallies in Lahore after several demonstrations turned deadly, but protests were allowed to go ahead in Karachi, Pakistan's largest city and economic hub. Protesters in downtown Karachi chanted "Down with the blasphemer," "Death to America," and "End diplomatic ties with European countries," according to an Associated Press reporter at the scene. About 25,000 people joined the rally organized by Tahafuz-e-Khatm-e-Nabuwat, a Sunni Muslim religious group, said Shaukat Shah, a Karachi police officer. The protest was the biggest in the port city since 40,000 rallied there on Feb. 16 against the cartoons, which first appeared in a Danish newspaper.