(CNN) -- For the second time in five months, Timbuktu's treasured collection of ancient manuscripts is under threat.
Earlier this year, it was thought that most of the 300,000 precious documents were destroyed by Islamic fundamentalists when the northern Mali conflict entered the fabled city.
But as it turns out, only 4,000 documents were burned by the rebels. The rest were smuggled out of Timbuktu six months before the incursion by a team of local families who have long safeguarded their city's famous library, often in their own homes.
The evacuation of the Timbuktu manuscripts was led by local librarian Abdel Kader Haidra and U.S. based book preservation expert Stephanie Diakité, who recruited local citizens and couriers to help them move more than 1,000 trunks of manuscripts by donkey cart, bicycle and boats to a safe house in the south of Mali.
Despite the dangers of the mission, both to the treasured texts and those involved in the evacuation, the vast majority of the manuscripts were saved, only to face a new threat.
The climate in the south of Mali is more humid than in Timbuktu and the fragile rag paper texts are now showing signs of mildew and rot.
"It would be the ultimate irony if all of these had survived the evacuation but had been destroyed because we don't have the resources to archival box them and insert humidity traps for the period they are in exile," said Diakité, who has now started an urgent campaign to raise the estimated $7 million it will cost to rescue the manuscripts.
The threat has been compounded, she said, by the pending rainy season in Mali which usually begins in the middle of June. Bamako, where the manuscripts are being held, has some of the country's heaviest rain.
Diakité is now calling on the global community to join the fight to save what she describes as an irreplaceable collection which includes works of poetry, fiction, commerce, medical theory and religious thought.
"Our ultimate goal is to return them to their home in Timbuktu," said Diakité.
But that won't happen, she said, unless the manuscripts can be protected now.