Cameroonian authorities have detained about 30 politicians and activists linked to opposition presidential candidate Issa Tchiroma, his campaign said on Sunday, heightening tensions ahead of Monday's announcement of results of an October 12 election.

Among those detained are Anicet Ekane, leader of the MANIDEM party, and Djeukam Tchameni, a prominent figure in the Union for Change movement. Both had supported Tchiroma's candidacy.

The arrests come amid clashes between security forces and Tchiroma's supporters in the cocoa- and oil-producing Central African nation.

Paul Atanga Nji, Cameroon's interior minister, confirmed during a press conference on Saturday that arrests had been made in connection with what he described as an "insurrectional movement," although he did not disclose the identities or total number of detainees.

'Insurrection scheme'

"Calls for protests by certain politicians with an obsession for power undoubtedly create conditions for a security crisis and contribute to the implementation of the insurrection scheme," Nji said.

In a post on his campaign's Facebook page on Sunday, Tchiroma rejected accusations of insurrection and alleged that government officials had sought to negotiate with some of those arrested before their detention.

Tchiroma, a former minister and once an ally of President Paul Biya, has claimed victory in the election and stated he will not accept any other result.

Protests have flared in several cities during the past week after partial election results reported by local media showed Biya was on course to be declared the winner.

Biya, aged 92, in power in Cameroon since 1982 and currently world's oldest ruling president, could continue for another seven years if the Constitutional Council declares him winner on Monday.