Algeria confirmed on Sunday that three of its diplomats, abducted by Islamist rebels in northern Mali in April, had been freed, but said the remaining four were still being held.
An Algerian security source and a Malian Islamist told Reuters on Friday that all seven diplomats had been released but there was no official comment on the matter until Sunday.
"I can say that three of our diplomats have been freed and are back home. What I can say also is that we are hopeful to see all seven diplomats handed over as quickly as possible," Foreign Minister Mourad Medelci told a news conference.
Algeria said in April its diplomats - a consul and six consular staff - were kidnapped from Gao, part of a swathe of territory in northern Mali then under the control of Tuareg-led separatists who had pushed out the military in a rebellion launched in January.
That rebellion has since been hijacked by a mix of local and foreign Islamist fighters who have taken control of northern Mali, imposing Islamic law and destroying ancient Sufi tombs in Timbuktu, classified by UNESCO as a world heritage site.
Western and African governments are struggling to muster a response to the crisis as politicians in the capital Bamako continue to squabble over how the country should be governed after a coup removed the president in March.
Algeria shares a border with Mali. Its diplomats may have been targeted because the Algerian government has been waging a long campaign against Islamist militants, including al Qaeda's North Africa wing, on its own territory.
Analysts and sources say Algeria is concerned about the turmoil in Mali but is reluctant to intervene lest it become embroiled in a messy cross-border conflict.