AKIPRESS.COM - Pregnant women and children are among more than 20 people who have been killed in tribal violence in Papua New Guinea, according to reports, Sky news reports.

Philip Pimua, a worker from the Department of Health who visited the scene, told Australian Broadcasting Corporation (ABC) he believed eight of those killed were aged between one and 15, and that two of the women were pregnant.

Philip Undialu, governor of the remote highland province of Hela, where the violence occurred, said 16 people including women and children were killed in an attack on the village of Karida on Monday.

That is thought to be retaliation for an earlier attack on a different village, Peta, that left around seven dead.

"This has escalated into the massacre of innocent women and kids," Mr Undialu said.

Reports of the number of dead and dates of the violence differ, however, and Hela Police Chief Inspector Teddy Augwi told the Post-Courier six people had been ambushed and killed near Peta on Saturday.

The newspaper, based in the South Pacific island nation's capital Port Moresby, reported as many as 24 people were killed in all, including two pregnant women, over three days of violence.