Latest violence comes amid tensions between DR Congo and Rwanda over M23, another rebel group.
At least 21 people were killed in the Democratic Republic of the Congo in the latest attack attributed to the Allied Democratic Forces (ADF) rebels on Saturday morning, a local civil society group said.
Later, Kivu Security Tracker (KST), which monitors violence in the region via a team of experts on the ground, revised the number on Twitter, saying that at least 27 civilians had been killed in the attack.
"We heard bullets at dawn in the village of Beu Manyama," army spokesman Anthony Mualushayi told AFP earlier Saturday.
"When we arrived, it was already too late because the enemy ADF had already killed more than a dozen of our fellow citizens with machetes."
The incident took place in the village of Beu-Manyama, 20 kilometers (12.4 miles) north of the Mamove town in the Beni territory of North Kivu province, Kinos Katuho, head of the Mamove civil society group, told reporters.
The attackers killed residents in their homes with machetes and bullets, Katuho said.
Last year, Congolese President Felix Tshisekedi authorized the Ugandan army to hunt down the ADF in the Beni and Irumu territories but the joint operations are yet to curb the violence.
Congo suspends RwandAir flights
Meanwhile, the Democratic Republic of the Congo announced on Saturday the suspension of RwandAir flights to the country amid escalating tensions with Rwanda.
The decision came on the heels of allegations that Rwanda is backing M23 rebels in recently renewed fighting in the eastern Democratic Republic of the Congo. Rwanda has denied the allegations.
“In view of the support of Rwanda to the M23 terrorists, it was decided to immediately suspend RwandAir flights to our country ... a warning to the Rwandan government which is disrupting the peace process,” said Patrick Muyaya, the Congolese minister for communication and media.
He also said the Congolese government has designated the M23 as a terrorist group.
There was no immediate comment from Kigali. But, Rwanda's flag carrier RwandAir said in a statement that it had canceled all flights to three Congolese cities, including Kinshasa, Lubumbashi, and Goma.
Two soldiers 'kidnapped'
Rwanda said on Saturday that two of its soldiers had recently been kidnapped by Congolese forces while they were patrolling along the border.
In a statement, the Rwandan Defense Forces said the soldiers, a corporal and a private, were kidnapped on March 23, the day when multiple rockets shelled by the Armed Forces of the Democratic Republic of Congo in the east were fired on Rwandan territory.
The kidnapping happened after the Congolese army along with Rwandan rebels of the Democratic Forces for the Liberation of Rwanda attacked the Rwandan army along the border, according to the statement.
“We call upon authorities of the Democratic Republic of Congo that work closely with these genocidal armed groups to secure the release of the Rwandan Defense Forces soldiers,” it said.