Al-Qaeda-linked fighters in Mali have threatened to "open the doors of hell" for French citizens if France kept pushing for armed intervention to retake the rebel-held north.
The renewed threats against French hostages and expatriates came on Saturday as French-speaking nations met in the Democratic Republic of Congo, where French President Francois Hollande was expected to urge the rapid deployment of an African-led force to rout the rebels.
Hollande said the threat would not deter France's determination to quash the rebels in Mali.
"If he continues to throw oil on the fire, we will send him the pictures of dead French hostages in the coming days," said Oumar Ould Hamaha, a spokesman for the armed group MUJWA, in apparent reference to the six French nationals still held by armed groups after being seized in the region.
"He will not be able to count the bodies of French expatriates across West Africa and elsewhere," Hamaha said by telephone.
MUJWA is among the groups which seized control of the northern two-thirds of Mali when fighters swept into the territory in April following a coup in the capital Bamako.
Regional and Western powers are now considering armed intervention to retake the area, with former colonial ruler France seeking swift military action by regional bloc ECOWAS.
The UN Security Council called on Friday for an intervention plan to be drawn up within 45 days after passing a French-drafted resolution to revive attempts to end the crisis.
Hollande on Saturday dismissed the MUJWA threat, saying it would not alter its stance on Mali.
"We have always said that we would always do everything to secure the release of our hostages," he told a news conference in Kinshasa.
"Should we tone down our message on the integrity of Mali, on the fight against terrorism, because of these threats? I think it's quite the opposite."
"It's by showing our determination to stand by our position of fighting terrorism that we can convince the abductors that it is time to free our hostages," he added.
Al-Qaeda's north African wing has threatened repeatedly to kill French hostages if Paris tries to mount a military intervention in Mali.
Seven workers for French firm Areva were seized in northern Niger in 2010, and all but four have since been released. Two other French citizens were taken hostage in Mali in November.
MUJWA's Hamaha said that the armed groups in the Sahara desert were largely funded by ransom payments from France and others.
"The top country who finances the jihadis is France," he said, adding that MUJWA could try to kidnap Hollande himself.
"I wonder what the international community would say if we took the French president hostage."