Gunmen killed at least 31 people in Pakistan's southern port city of Karachi as a by-election was held Sunday to replace a lawmaker murdered earlier this year.
The violence broke out Saturday night when gunmen opened fire in several parts of the city ahead of the vote. Police say they have arrested at least 20 suspects in connection with the killings.
The election was being held to replace provincial lawmaker Raza Haider from the Muttahida Quami Movement (MQM), who was gunned down in August. The assassination sparked four days of violence that killed at least 85 people.
MQM, which largely represents the Urdu-speaking community, and the rival Awami National Party, representing ethnic Pashtuns, blamed each other for the violence.
Karachi has been plagued by ethnic and sectarian killings, crime and kidnappings.
Some information for this report was provided by Reuters.