More than 200 civilians held captive in the east of the Democratic Republic of Congo by an armed group linked to the Islamic State have been rescued in an army operation, the military in neighbouring Uganda has said.

Ugandan soldiers, working with their Congolese counterparts, targeted a camp controlled by the Allied Democratic Forces (ADF), a militant group that has its origins in Uganda.

Children were among those freed, the youngest being a 14-year-old girl, according to a Ugandan statement.

The ADF was originally formed in Uganda in the 1990s by people disgruntled with the government's treatment of Muslims. But after being routed by the army there, the remnants fled across the border.

In 2021, Uganda and DR Congo launched a joint offensive to drive the ADF out of their Congolese strongholds, but it has so far failed to put an end to the group's attacks.

It is not clear when or where the rescued civilians were abducted but the Ugandan army statement said that those who were being held described "harsh conditions in captivity, including lack of food, forced labour and punishment for disobedience".

Some also seemed frail and were suffering from malaria, breathing difficulties and exhaustion, the authorities said.

"You are not under detention. You are victims of abduction, and we shall ensure you are handed over to the relevant authorities so you can reunite with your families," Maj Gen Stephen Mugerwa, who leads the joint Uganda-Congolese mission, is quoted as telling those who had been freed.

The army said that several ADF fighters were killed in the attack on the camp and a cache of weapons was recovered. The statement does not say if there were any casualties among the Ugandan or Congolese military.

ADF rebels have been operating from inside DR Congo for the past two decades.

Its leader Musa Seka Baluku reportedly first pledged allegiance to IS in 2016, but it was not until April 2019 that IS first acknowledged its activity in the area.

After years of not operating openly in Uganda, the ADF has been blamed for a series of attacks in recent years, including suicide bombings in Uganda's capital, Kampala, in 2021 and the targeting of schools in western Uganda in 2023.

But in eastern DR Congo it has become notorious for its kidnapping and killing.

A 2024 study by BBC Monitoring found that the ADF was responsible for more than half of the civilian deaths in that conflict-hit region.

At the end of last year, a researcher for the rights group Amnesty International reported how the killings and abductions by the ADF were happening with "alarming frequency". Women and girls were being used as sexual slaves, Rawya Rageh added.

"Men, women and children told me how they ran for their lives as fighters armed with blades and guns descended on their villages.... Released hostages talked of agonising spells – sometimes months and years – spent in captivity, practically starved and forced to do various tasks in ADF camps."