The voting was set to start at 8am but it was delayed by around half-an-hour due to late arrival of polling staff at the polling stations. The polling continued till 5pm.
As many as 3,57,000 voters were expected to use their right of franchise in the election and the voters turnout remained good at the end of day. A total of 213 polling stations were established in the constituency. Closed circuit cameras were also installed and law enforcement personnel deployed in and outside the polling stations.
Related story: The NA-246 bye-election — a curtain-raiser
MQM’s Kanwar Naveed Jameel, PTI’s Imran Ismail and Rashid Naseem of Jamaat-e-Islami are the key contestants in the by-poll among total 11 candidates vying for the seat.
— LIVE UPDATES —
5:07pm – According to unofficial results from a polling station at Government City College, Moosa Colony, MQM candidate Kanwar Naveed got 780 votes followed by 102 votes to JI’s Rashid Naseem. PTI’s Imran Ismail got only a few votes.
5:00pm – The polling time has ended. ECP has announced not to extend voting time.
4:44pm – Commissioner Karachi Shoaib Ahmed Siddiqui says polling process is going on with complete transparency and fairness.
4:23pm – Rangers personnel have taken three persons into custody for chanting slogans and disrupting polling environment. They were arrested from a polling station in Block 14 of F.B. Area.
4:02pm – According to some reports, voters turnout today stood around 160,000 uptil now.
3:41pm – A voter at a polling station in Sharifabad area complained he was subjected to unkind treatment from law enforcers.
3:20pm – MQM candidate Kanwar Naveed Jameel has written a letter to the election commission, seeking extension of two hours in the polling, which ends at 5pm.
3:05pm – DIG West Feroz Shah has informed that 30 areas of NA-246 will be sealed in next hour due to security threats.
2:41pm – JI leader Hafiz Naeeumur Rehman, in a press talk, alleges that rigging was carried out at some polling stations after power supply was disconnected there.
Hafiz Naeem-ur-Rehman comments on MQM slogan by arynews
2:30pm – MQM chief Altaf Hussain begins his address to party workers and senior leaders. He demanded extension in polling time by three hours.
Read here: No force can stop MQM from victory: Altaf
2:15pm – Voters at some polling stations alleged that polling process is ‘deliberately’ being slowed.
1:49pm – The Election Commission has announced that polling time will not be extended. ECP reiterates that polling will continue till 5pm without any break.
1:30pm – The paramilitary force confirms arrest of two persons involved in vote rigging at a polling station in Karimabad. One is Syed Majeed Ali (presiding officer) and another is Rehan Ahmed. The latter is sentenced to six months in prison with Rs5,000 fine.
1:10pm – Rangers personnel have arrested a presiding officer Syed Majeed Ali for letting fake votes be cast at a polling station set up in Karimabad school. He is sentenced to three months in prison.
Read here: Two including presiding officer arrested for vote rigging
12:52pm – PTI chief Imran Khan says MQM has sensed that they are not going to bag 1,37,000 votes which they got in the last poll. Khan said it is good to see MQM fighting for the seat which was not their practice in previous polls.
12:40pm – Jamaat-e-Islami has informed ECP that some suspected persons are present at polling station numbers – 11, 12, 13 and 14 – and demanded against it.
12:26pm – Rangers personnel have arrested two suspected persons from polling station in Muslim Government School.
12:18pm – MQM has demanded extension in polling time by three hours.
Read here: MQM claims voters being subjected to harsh test
12:05pm – MQM leader Farooq Sattar is holding an emergency press conference, alleging that several voters are being barred from casting their vote.
11:35am – Inspector General Sindh is paying visit to different areas of the constituency to inspect security arrangements.
11:19am – Several voters, majority of them women, complain of being barred from casting their vote at a polling station in Comprehensive School in the constituency.
11:07am – Polling stations number 172 and 173 have been shifted owing to power outages. While a polling station established at Aga Khan Community Centre has been shifted to Okhai Memon Community Centre.
Slow voting process is also part of deliberate method to dissuade possible voters mostly happens in non—stronghold areas #NA246VoteForBat
— Awab Alvi (@DrAwab) April 23, 2015
11:05am – Several women at polling station in Siraj-ud-Daulah College claimed they were not being allowed to cast their vote despite having original CNIC and their name enlisted in the voters list. 10:50am – K-Electric team has reached Apwa College Karimabad to fix electricity problem. 10:45am – Heavy turnout of voters is being witnessed at polling stations in Liaquatabad. 
10:36am – PTI candidate Imran Ismail says today’s by-poll in Karachi will be a historic one. 10:30am – Reports coming in that MQM will hold emergency press conference at 11am today. 10:18am – ECP receiving several complaints that polling could not kick off at scores of polling stations. 10:07am – The power supply went off at some polling stations including Apwa College Karimabad. CCTV cameras have also stopped working due to power outage. K-Electric had issued a statement yesterday vowing to ensure uninterrupted electricity supply at all polling stations in the constituency.
Why these Male Rangers Personnel doing at Lady Polling Station? Is he suppose closely like this? #VoteForPatang pic.twitter.com/l1iLKKeJez — Wasay Jalil (@WasayJalil) April 23, 2015
9:50am – The voting could not begin at polling station in Apwa College in Karimabad, throwing voters into disarray.
9:42am – MQM candidate Kanwar Naveed Jamil has said his party is satisfied with the overall conduct of Rangers deployed at polling stations.
9:31am – Polling staff found absent at a number of polling stations. The election commission has ordered despatching reserved staff at all such spots.
9:26am – DG Rangers Sindh Major General Bilal Akbar visited the Election Commission office in District Central and discussed by-poll arrangements with the officials including returning officers.
9:14am – According to officials, polling process will continue without any break till 5pm.
9:09am – Rangers personnel are carrying out searching of voters before letting them enter in polling stations.
9:01am – The authorities have declared all polling stations as sensitive.
8:50am – MQM candidate Kanwar Naveed Jamil has reached Siraj-ud-Daulah College to inspect arrangements. Rangers personnel were also present inside the polling station.
8:42am – According to ARY News, voters at some polling stations lodged protest over delayed beginning of the polling process.
8:35am – The Election Commission has decided to conduct strict monitoring of the entire polling process.
8:32am – Voters are barred from carrying cellphones in the polling stations.
8:30am – At least 5,000 security personnel have been deployed for security of by-polls in the constituency.
