KARACHI, Pakistan (AP) - It's been a deadly 24 hours in Pakistan's largest city.
      
Gunmen have killed at least 25 people in Karachi as voters cast ballots today for a replacement for a provincial lawmaker. The lawmaker was murdered in August.
      
Police say the motives behind the latest shootings are under investigation, and they aren't ready to say they are all politically motivated. But many so-called "target killings" in the city have been linked to gangs controlled by a groups that include the city's two main political parties.
      
Karachi's police chief notes that the killings were not confined to the area where the elections were being held. He says at least three of the killings do not seem to be politically motivated and were carried out during "other criminal offenses." Police have arrested at least 20 suspects.