Reports from Papua New Guinea say four people have been killed in election-related violence in the highlands.
Voting for a new parliament lasts nearly two weeks but there have been delays and allegations of irregularities.
One man was shot dead by supporters of a rival candidate in Mount Hagen where businesses were shut for security reasons.
Ray John, a nursing officer at the Mount Hagen General Hospital says six people were injured in a fight at the hospital, which houses one of the polling stations.
Violence was also reported around the capital, Port Moresby, with police firing weapons into the air and beating frustrated voters.
Witnesses say only five of 71 polling stations were open in Port Moresby because of security concerns and because election officials had not been paid.
Irregularities including long delays and missing ballot boxes and papers have been reported in almost every district since polls opened on Saturday.