Nigeria's governing party charged Thursday that 32 of its members have been shot, clubbed and beheaded in escalating violence as oil-rich Rivers state prepares for a rerun of legislative elections previously annulled amid fraud and killings.

Rivers state is a stronghold of the opposition Democrats. The party denies responsibility and blames the spate of killings over two weeks on "satanic cult clashes," according to state government spokesman Austin Tam George, who is also an official of the Democrats party. He accused the governing party of "reckless and false allegations" to destabilize the opposition administration.

Rivers police spokesman Ahmad Muhammad acknowledged there had been "some murders" and said the gang leader believed to be behind it has been arrested.

The state committee of President Muhammadu Buhari's All Progressives Congress accused opposition leaders of hiring gangsters to kill and intimidate its members. Party members are "fast becoming an endangered species" and fear will keep many from the March 19 polls for federal and state legislators in the southern state, it said in a statement.

It released a list of 32 names of party members it said have been killed, some by gunshots, several beheaded, others clubbed to death and one man burned alive.

"It is most likely that the violence is going to get worse," warned Dakuku Peterside, who lost the governorship election in Rivers.

The 2015 presidential and legislative elections were relatively peaceful except in Rivers, where the National Human Rights Commission said nearly 100 people died.