Seven people were killed and dozens injured in firing in Liaquatabad, Baldia and Saeedabad during polling in the by-election for three national and one provincial assembly seats in Karachi on Wednesday, police said.
The polling began at 8 am and continued till 5 pm.
During the entire day sporadic incidents of rowdism and lawlessness were witnessed in the constituencies where polling was held. Deputy Inspector General of Police Tariq Jameel said that 15 people were arrested from the disturbed areas.
The DIG said that polling remained peaceful for most of the time but mobs at certain places turned violent in the last one hour of the voting. Violent mobs used firearms.
An incident of explosion, which took place in Baldia Town did not cause any damage.
Sources said that a firecracker, brought in a basket of tomatoes and placed on a wheelbarrow by unknown motorcycle rider in Baldia Town, exploded but did not cause any damage to life or property.
The voters' turnout remained low as many candidates had made inadequate transportation arrangement for voters. Some of the candidates remained in the impression that popularity of their parties would attract voters. It did not happen.
The city government had announced local holiday to facilitate voter to exercise their rights of franchise.
AGENCIES ADD: "The MQM has lost three members and the MMA two," Tariq Jameel told Reuters. "Identity of two others remains unknown," he said.
Police said the other two dead had yet to be identified.
At least 29 people belonging to the rival political parties, including Pakistan People's Party, sustained bullet wounds, police said.
At least five vehicles were set ablaze, police said.
"But thank God, violence has stopped now and the situation is now under control," Jameel said.
The three National Assembly seats fell vacant as the Muttahida Qaumi Movement (MQM) asked its MNAs to resign on corruption charges. The Sindh Assembly by-election follows the murder of a PPP MPA by unidentified gunmen a few months ago.
Both parties blamed each other for the violence.
"They have terrorised the entire neighbourhoods," said MQM spokesman Kanwar Khalid Younus. "Their militants have been roaming, firing with automatic weapons. We are the victims."
Muttahida Majlis-i-Amal spokesman Sarfraz Ahmed accused the MQM of trying to rig the elections. "They are attacking our workers," he said.
Sherry Rehman, a PPP MNA, accused the government officials of massive vote rigging.
"In a number of polling stations they are stuffing ballot boxes," she said. "Our members and polling agents were beaten up and forced to leave the polling stations in many areas."
The MQM is expected to dominate the by-elections.