A Sudanese rebel group said on Friday it had launched a military campaign focused on derailing elections slated for next month, as rebels and the government reported fresh clashes.
The statement by the Sudan People's Liberation Army-North Sector (SPLM-N) marks the first time a major rebel group has explicitly said it is aiming to force the government to cancel the election through armed action.
"The military campaign will reach cities and villages under the control of the (ruling) National Congress Party to prevent Bashir from re-electing himself as president once again," SPLM-N spokesman Arnaud Lodi said in a statement.
The SPLM-N statement said there had been clashes in South Kordofan, while a representative of the Sudan Liberation Movement, a major Darfuri armed group, said there had been clashes in Jebel Marra in Darfur.
An army spokesman confirmed the clashes but dismissed the SPLM-N's campaign.
"That is just talk for media consumption," said Colonel Al-Sawarmi Khalid.
Sudan has faced a rebellion in Darfur since 2003 and a separate but linked insurgency in Blue Nile and South Kordofan since the secession of South Sudan in 2011.
Violence on both fronts has increased in past months.
Meanwhile, the mainstream political opposition has abandoned a national reconciliation process, announced a boycott of the polls, and launched a campaign to push for the exit of President Omar al-Bashir after 25 years of his rule.
Bashir has been giving confident campaign speeches for several weeks now in the run-up to the presidential and parliamentary polls, and is currently at an economic conference in the Egyptian resort town of Sharm el-Sheikh.
The rebels said their offensive was in solidarity with the opposition's moves to force Bashir's exit.
"The goal of the military campaign is to integrate the diverse paths of the struggle -- the armed uprising and civil disobedience -- in order to stop the elections and bring down the autocratic system," Lodi said.
The political opposition could not be immediately reached for comment.
The SPLM-N is made up of former civil war fighters who were left in northern Sudan after the south seceded in 2011. They have since joined Darfuri rebels and some political groups in a loose coalition pushing for the end of Bashir's rule.