JUBA (Reuters) - Gunfire erupted in South Sudan's capital on Friday, a day after a clash between rival factions killed at least five people, a Reuters witnesses reported.

President Salva Kiir and former rebel leader Riek Machar, who is now vice president, called for calm in comments to journalists at the presidential State House, one Reuters witness at State House said, adding that shooting could be heard nearby.

Another Reuters witness said fighting seemed to erupt in the area around State House. Kiir's SPLA and Machar's opposition SPLA-IO, which fought during a conflict lasting more than two years, have forces in that area, the witness said.

(Reporting by Denis Dumo and Reuters Television; Writing by Edmund Blair; Editing by Gareth Jones)