A prominent Malian opposition leader and a French aid worker were among four hostages to have been released by suspected fighters, Mali’s presidency said.

Soumaila Cisse, 70, and Frenchwoman Sophie Petronin, 75, who were believed to have been held by al-Qaeda-affiliated fighters, were on their way to the capital, Bamako, following their release, Mali’s presidency said on Twitter on Thursday.

Italian hostages, Nicola Chiacchio and Pier Luigi Maccalli, were also freed on Thursday, the president’s office said in a statement read on national television.

The French Embassy in Bamako’s Twitter account also shared the news, adding: “AT LAST!”

The hostages’ release followed the freeing by Malian authorities of nearly 200 suspected fighters over the weekend, which had fuelled speculation that a prisoner exchange was imminent.

Malian and French authorities had neither confirmed nor denied that talks about a potential prisoner swap were continuing.

Cisse, a three-time presidential candidate, was abducted on March 25 while campaigning in his home town of Niafunke in central Mali ahead of a parliamentary election. He is a popular politician who served as finance minister in the 1990s.

Petronin, who ran a charity for malnourished and orphaned children, was abducted near the northern city of Gao in late 2016. She was the last French national held hostage in the world.

Mali has been struggling to contain an armed rebellion that first emerged in 2012, and which has since killed thousands of people.

The volatile West African nation has been plagued by armed groups for years, some of which have pledged allegiance to the ISIL (ISIS) armed group and al-Qaeda networks.

A United Nations peacekeeping mission is supporting the peace process in Mali after the north of the country temporarily fell into the hands of rebels in 2012, while France has stationed about 5,100 soldiers in the Sahel region.