A South Sudanese official says a new rebel group has formed against the government months after a peace deal was signed with another rebel group to end a deadly civil war.

Information Minister Michael Makuei Lueth told reporters Tuesday that the new group led by veteran politician Ali Tamim Fartak has fought with government troops in the remote Wau region, leading to the reported deaths of about 39 civilians and four police.

The minister said the government has not yet confirmed the deaths.

Fartak could not be reached for comment.

Lueth said the new rebel group has an Islamic fundamentalist agenda and includes former government troops, fighters from the Ugandan-led rebel group the Lord's Resistance Army and a Sudanese militia called the janjaweed.