'Hundreds held' in Bhutto raids
The party of Pakistan's former PM Benazir Bhutto has said more than 700 members were arrested overnight ahead of a planned mass rally on Friday.
They were held under emergency measures brought in on Saturday by President Pervez Musharraf, the party said.
Separately in Karachi, five people were charged with sedition, which can carry the death penalty.
The moves came hours after US President George W Bush told Gen Musharraf in a "frank" phone call to hold polls soon.
Mr Bush told Gen Musharraf he could not be both army head and president.
Gen Musharraf has said he declared the state of emergency because of a crisis caused by militant violence and an unruly judiciary.