GOMA, Democratic Republic of Congo (Reuters) - The bodies of 26 people believed killed after an ambush last week in eastern Democratic Republic of Congo have been discovered, most of them with their hands tied and their necks broken, a local chief said on Sunday.

The victims disappeared a week ago after they were ambushed by militants on a main road in North Kivu’s restive Beni territory, where more than 800 people were killed in dozens of massacres between 2014 and 2016.

The attack, which followed a lull this year, has revived questions about the state’s ability to impose order over eastern borderlands wracked by ethnic tensions and competition for mineral resources.

Congolese authorities and U.N. officials initially believed that about 20 civilians had disappeared after being attacked by armed assailants and were likely to have been killed. They were unable to locate the bodies for days, however, due to intense fighting.

A group including officials from Congo’s U.N. mission MONUSCO, the army, the Congolese Red Cross, and Congolese authorities traveled to the scene of the killings on Sunday.

“In total, 26 people -- three women, 22 civilian men and one Congolese soldier -- were tied up and killed by breaking their necks,” Saambili Bamukoka, chief of Beni’s Watalinga chiefdom, told Reuters.

A Congolese military spokesman had earlier confirmed that the bodies had been discovered near the road, but did not know how many there were.

“Bodies were found in a state of decomposition,” said local army spokesman Mak Hazukay, adding that the road remained closed to civilian traffic. “We must first have the time to secure the surrounding area.”

The day after the attack on the travelers, militants assaulted two nearby military bases, killing two U.N. peacekeepers and injuring 18 others.

The army and U.N. peacekeeping mission blamed the raids on the Allied Democratic Forces (ADF), a Ugandan Islamist group active near the border. Authorities have also accused the ADF of carrying out nearly all the massacres of the past three years.

But independent and separate U.N. experts say several armed groups as well as national army commanders have been involved in the killings as they vie for influence in Congo’s lawless eastern borderlands.

Millions died in regional wars that ravaged eastern Congo between 1996-2003 and spawned dozens of armed groups that continue to prey on local populations.