A separatist coalition in Mali says it will oppose efforts to hold local elections next month, potentially worsening an already fragile security situation in the country's north.

Mali's government announced in August that it would organize regional and local elections on Oct. 25. The vote would help extend the government's authority in the north, which fell under control of Tuareg separatists and al-Qaida-affiliated Islamic extremists following a military coup in 2012.

But a spokesman for the main separatist coalition said this week that the timeline was "inconceivable." Almouzamile Ag Mohamed said a June peace accord requires that a transition team be established in the north first.

A document dated Sept. 9 and signed by the coalition's military leaders said attempts to campaign in northern separatist-held territory "will be punished."