At least 33 people were killed in election violence Saturday as the right-wing coalition that defeated Benazir Bhutto took an early lead in provincial races.

Officials said it was the bloodiest election in Pakistan's 43-year history.In southern Sindh Province, gunmen ambushed a car taking the son of caretaker Prime Minister Ghulam Mustafa Jatoi to vote, officials said. He ran for safety into the polling station, officials said.

The province is the power base of Bhutto, the former prime minister whose Pakistan People's Party was defeated in Wednesday's national elections. Legislative elections in Punjab, Sindh, Baluchistan and Northwest Frontier provinces were seen as a test of strength for the Islamic Democratic Alliance, a loose-knit coalition of 18 parties that will form the next national government.