"This new document... shows we are no longer dealing with an isolated local problem, but with an enemy which is reaching across continents to share advice," said Bruce Riedel, a 30-year veteran of the CIA, now the director of the Intelligence Project at the Brookings Institute.

While some of the tips are outdated or far-fetched, taken together, they suggest the Islamists in Mali are responding to the threat of drones with sound, common-sense advice that may help them to melt into the desert in between attacks, leaving barely a trace.

"These are not dumb techniques. It shows that they are acting pretty astutely," said Col Cedric Leighton, a 26-year-veteran of the United States Air Force, who helped set up the Predator drone program, which later tracked Osama bin Laden in Afghanistan.

"What it does is, it buys them a little bit more time - and in this conflict, time is key. And they will use it to move away from an area, from a bombing raid, and do it very quickly," he said.

The success of some of the tips will depend on the circumstances and the model of drones used, Col Leighton said. For example, from the air, where perceptions of depth become obfuscated, an imagery sensor would interpret a mat stretched over the top of a car as one lying on the ground, concealing the vehicle.

New models of drones, such as the Harfung used by the French or the MQ-9 "Reaper," sometimes have infrared sensors that can pick up the heat signature of a car whose engine has just been shut off. However, even an infrared sensor would have trouble detecting a car left under a mat tent overnight, so that its temperature is the same as on the surrounding ground, Col Leighton said.

Unarmed drones are already being used by the French in Mali to collect intelligence on al-Qaeda groups, and US officials have said plans are underway to establish a new drone base in northwestern Africa.

The US recently signed a "status of forces agreement" with Niger, one of the nations bordering Mali, suggesting the drone base may be situated there and would be primarily used to gather intelligence to help the French.

The author of the tipsheet found in Timbuktu is Abdallah bin Muhammad, the nom de guerre for a senior commander of al-Qaeda in the Arabian Peninsula, the Yemen-based branch of the terror network.

The document was first published in Arabic on an extremist website on June 2, 2011, a month after bin Laden's death, according to Mathieu Guidere, a professor at the University of Toulouse.

Prof Guidere runs a database of statements by extremist groups, including al-Qaeda in the Islamic Maghreb, and he reviewed and authenticated the document found by the AP.

The tipsheet is still little known, if at all, in English, though it has been republished at least three times in Arabic on other jihadist forums after drone strikes took out US-born cleric Anwar al-Awlaki in Yemen in September 2011 and al-Qaeda second-in-command Abu Yahya al-Libi in Pakistan in June 2012.

It was most recently issued two weeks ago on another extremist website after plans for the possible US drone base in Niger began surfacing, Prof Guidere said.

"This document supports the fact that they knew there are secret US bases for drones, and were preparing themselves," he said. "They were thinking about this issue for a long time."

The idea of hiding under trees to avoid drones, which is tip No 10, appears to be coming from the highest levels of the terror network. In a letter written by bin Laden and first published by the US Center for Combating Terrorism, the terror mastermind instructs his followers to deliver a message to Abdelmalek Droukdel, the head of al-Qaeda in the Islamic Maghreb, whose fighters have been active in Mali for at least a decade.

"I want the brothers in the Islamic Maghreb to know that planting trees helps the mujahedeen and gives them cover," bin Laden writes in the missive. "Trees will give the mujahedeen the freedom to move around especially if the enemy sends spying aircrafts to the area."

Hiding under trees is exactly what the al-Qaeda fighters did in Mali, according to residents in Diabaly, the last town they took before the French stemmed their advance last month. Just after French warplanes incinerated rebel cars that had been left outside, the fighters began to commandeer houses with large mango trees and park their four-by-fours in the shade of their rubbery leaves.

Hamidou Sissouma, a schoolteacher, said the Islamists chose his house because of its generous trees, and rammed their trucks through his earthen wall to drive right into his courtyard. Another resident showed the gash the occupiers had made in his mango tree by parking their pickup too close to the trunk.

In Timbuktu also, fighters hid their cars under trees, and disembarked from them in a hurry when they were being chased, in accordance with tip No 13.

Moustapha al-Housseini, an appliance repairman, was outside his shop fixing a client's broken radio on the day the aerial bombardments began. He said he heard the sound of the planes and saw the Islamists at almost the same moment. Abou Zeid, the senior al-Qaeda emir in the region, rushed to jam his car under a pair of tamarind trees outside the store.

"He and his men got out of the car and dove under the awning," said Mr al-Housseini. "As for what I did? Me and my employees? We also ran. As fast as we could."