More than 30 people were killed in attacks by suspected extremist forces on Sunday and Monday in northeast DR Congo's troubled Ituri province, the local Red Cross said.

Rebels from the Allied Democratic Forces (ADF), one of the most notorious armed groups, "attacked the population" in two villages around Komanda, 75 kilometers (45 miles) south of provincial capital Bunia, said David Beiza, head of the Red Cross in Ituri's Irumu territory.

As well as attacking the villages of Mangusu, where 17 civilians died, and Shauri Moya, where nine were killed, the assailants also targeted a bridge over the Ituri River, killing four more, Beiza said.

The Kivu Security Tracker (KST), a respected monitor, reported later on Twitter, "at least 18 civilians were killed in Mangusu village ... on Monday," adding that "the ADF is suspected."

The monitoring group didn't mention any toll figure for Shauri Moya village. "Since yesterday, we have heard light and heavy gunfire coming from Mangusu and Shauri Moya," confirmed Daniel Herabo, a local civil society leader.

According to Herabo, the rebels first entered Shauri Moya on Sunday and then Mangusu on Monday morning.

"There, the bodies of some of the 17 victims were tied up, others had their throats slit and others had been shot dead," said Herabo, who has not visited the villages, but relied on colleagues in the area.

He said fighting between the ADF and the FARDC (DRC armed forces) was continuing on Monday afternoon.

The ADF rebels, who are presented by the Daesh group as its central African affiliate, have meted out extreme violence against civilians – often with machetes and other bladed weapons.

The villages attacked are just 12 kilometers from Drakpa town where 14 civilians, including seven children, were killed in a camp for displaced people days earlier.

Ituri and the neighboring North Kivu province are currently under an official state of siege, declared last May.

Under it, civilian leaders have been replaced by military or police officers, with the declared aim of boosting a crackdown on armed groups. That measure has so far failed to bring peace to the region.

In late November, Ugandan troops joined DR Congo's army in an operation against the ADF, following bomb attacks in the Ugandan capital Kampala that were blamed on the group.

The region has been in the grip of armed groups for a quarter of a century, many of them a legacy of the Congo Wars of the 1990s and early 2000s.

Democratic Republic of Congo Prime Minister Jean-Michel Sama Lukonde is heading a ministerial delegation to visit the two provinces, which began in North Kivu capital Goma on Monday to take stock of the state of siege.