BENI, Democratic Republic of Congo- U ganda and Democratic Republic of Congo launched joint air and artillery strikes in eastern Congo on Tuesday against an Islamic State-linked militia known as the Allied Democratic Forces (ADF), both countries said.

Based in Congo since the late 1990s, the ADF is blamed for killing hundreds of villagers in the east of the country in raids after it pledged allegiance to Islamic State in mid-2019.

IS has in turn claimed responsibility for some of the ADF's violence, including a string of recent bombings in Uganda, but United Nations researchers have found no evidence of IS command and control over ADF operations.

Ugandan army spokeswoman Flavia Byekwaso said she was yet to receive details of the attacks on ADF bases, but they would not be a one-off.

"As announced, the targeted and concerted actions with the Ugandan army started today with airstrikes and artillery fire from Uganda on the positions of ADF terrorists in the DRC," Congo government spokesman Patrick Muyaya said on Twitter.

The joint offensive is the first time Uganda has publicly intervened against the ADF in Congo since a brief campaignin December 2017.

A local chief and a resident said they heard explosions on Tuesday morning in Watalinga territory, North Kivu province, in the borderlands of eastern Congo.

"There is a real panic here at home, especially because we were not informed of this situation," said resident Julien Ngandayabo. "We have suffered too much with the ADF, who have massacred our families. We are waiting to see if this is the solution."

Pascal Saambili, head of the Watalinga chiefdom, said the community woke to the sound of heavy bombardment which continued during the morning.

A Congo army spokesman, Antony Mwalushay, said three ADF fighters were killed and three wounded during intense fighting at Semuliki bridge, which connects the city of Beni to Uganda. One Congolese soldier was killed, he added.

A triple suicide bombing in Kampala on Nov. 16, which killed seven people, including the bombers, was the third Islamic State has claimed in Uganda.

Uganda's response risked triggering a wave of retaliatory attacks against civilians, as well as stoking regional rivalries, a conflict analyst said.

"On paper the Ugandan army are targeting the ADF, but in practice this kind of intervention could cause massive upheaval and suffering, while also re-energising some other Congolese armed factions on the ground," said Dino Mahtani from Brussels-based think-tank International Crisis Group.

(Reporting by Ayenat Mersie, Elias Biryabarema, Erikas Mwisi Kambale and Hereward Holland; writing by Hereward Holland; Editing by Raissa Kasolowsky, Andrew Cawthorne and Timothy Heritage) ((bate.felix@thomsonreuters.com; +33 1 49 49 55 70 Twitter: @BateFelix;))