The leader of so-called Islamic State in the Greater Sahara (ISGS) died of wounds from a drone strike that hit him on a motorcycle last month in southern Mali, French authorities have said.

The French government did not disclose how they had identified him as Adnan Abu Walid al-Sahrawi, whose group has terrorised the region, and the claim could not immediately be independently verified.

But the authorities declared the killing – in a French-led operation involving back-up from US, EU, Malian and Nigerian military forces – a major victory against jihadists in Africa and justification for years of anti-extremist efforts in the Sahel.

French government officials described al-Sahrawi as “enemy No 1” in the region, and accused him of ordering or overseeing attacks on US troops, French aid workers and between 2,000 and 3,000 African civilians – most of them Muslim.

Experts called the announcement big and welcome news for governments struggling against violent extremists, but warned that ISGS could find a new leader, and that the threat of jihadist violence remained high.

“The death of al-Sahrawi will likely disrupt ISGS operations in the short-term. But it is unlikely to permanently cripple the extremist group,” Alexandre Raymakers, senior Africa analyst at risk intelligence company Verisk Maplecroft, said.

He called it a “tactical success” for Operation Barkhane, considering that al-Sahrawi’s elimination had been a top priority for the French military, but noted that despite the loss of several senior leaders to French military operations over the years, the jihadist group had continued to expand its footprint in the Sahel.

“This reinforces our determination to fight terrorism with our partners in the Sahel, with our American and European partners,” French defence minister Florence Parly said.

“We will not leave the Sahel.”

Intelligence gleaned from the capture of ISGS fighters earlier this year allowed France to hone in on specific areas where al-Sahrawi was likely to hide, Ms Parly said.

He was on a motorcycle with one other person when they were hit by a drone strike in the Dangalous Forest near the Niger border on August 17, one of several airstrikes in the region in mid-August, Thierry Burkhard, chief of staff of France’s military, said.

France then sent a team of 20 special ground forces to the region to verify the identities of those hit, and determined that about 10 ISGS members had been killed, including al-Sahrawi, according to Mr Burkhard.

French president Emmanuel Macron announced the death overnight, after authorities took time to verify his identity.

According to Mr Macron’s office, al-Sahrawi personally ordered the killing of six French aid workers and their Nigerien colleagues last year, and his group were behind a 2017 attack that killed four US troops and and four Niger military personnel.

His group had also abducted foreigners in the Sahel and was believed to still be holding American Jeffrey Woodke, who was abducted from his home in Niger in 2016, as well as a German hostage.

“The leader of the Islamic State was one of the biggest criminals and (IS) was one of the most violent groups that killed many people in the Sahel,” Mahamoudou Savadogo, a conflict analyst and former military officer in Burkina Faso, said.

He said this death would “unburden” local communities and governments in the region.

The extremist leader was born in the disputed territory of Western Sahara and later joined the Polisario Front. After spending time in Algeria, he made his way to northern Mali where he became an important figure in the group known as MUJAO.

MUJAO was loyal to the regional al Qaida affiliate. But in 2015, al-Sahrawi released an audio message pledging allegiance to the IS group in Iraq and Syria.

France, the region’s former colonial power, recently announced that it would be reducing its military presence in the area, with plans to withdraw 2,000 troops by early next year.

But Ms Parly insisted that France would not pull out entirely, saying the attack was proof that international co-operation in the region was bearing fruit.