Violence erupted in Karachi ahead of the by-poll in PS-94, Orangi Town on Sunday.

At least 33 people were killed and 50 other injured in separate incidents of firing in different parts of the metropolitan on Sunday.

According to the sources, the incidents took place various areas including Gulistan-e-Jauhar, Sadar, Orangi Town, Baldia Town, Kemari, Maskan, Dhobi Ghat and Kharadar.

Unidentified mob torched 4 vehicles in different areas late on Saturday.

On Sunday morning, 2 passengers were died and other 3 sustained injuries when unidentified gunmen opened fire on Mini Bus in Banaras.

The MQM accused the ANP of carrying out the killings, an allegation it denied.

"Soon after announcing its boycott of the by-election, ANP's workers began killing innocent citizens in a bid to sabotage the election process," the party said in a statement.