Unidentified gunmen opened fire at campaign workers in Sri Lanka's capital on Friday, killing one and wounding 13, police and hospital officials said, in the first major political violence before the parliamentary election.

The workers were campaigning for Finance Minister Ravi Karunanayake of the United National Party.

Police spokesman Ruwan Gunasekara says the gunmen shot at the campaign workers from a vehicle and fled the scene. He said police investigations are underway to arrest the culprits.

Colombo National Hospital director Dr. Anil Jasinghe said one woman was brought dead to the hospital and 13 people are being treated for gunshot wounds.

Sri Lanka's parliamentary election will be held Aug. 17. The election process has been largely peaceful.