At least 31 people have been killed in attacks in northeastern Democratic Republic of the Congo.

Militias shot dead 22 people attending a funeral service on Saturday, army spokesman Jules Ngongo told the German Press Agency on Sunday.

16 other people were injured.

Earlier, armed rebels had killed nine people in another village and burned down 20 houses there, it said.

The army blamed the Islamist militia ADF for this attack.

The rebel group ADF, which was founded in neighboring Uganda, regularly carries out bloody attacks in eastern Congo.

The US government has classified the ADF, an offshoot of the Islamic State (IS) militia, as a global terrorist organization.

Several militias are active in the north-east of the Congo, which has a population of almost 90 million.

They are mostly concerned with controlling valuable natural resources such as copper, cobalt, gold and diamonds.