At least 17 people have been killed during protests in the Congolese capital on Monday.
The dead include three police officers, with one witness telling Reuters they saw a crowd burning the body of an officer.
A march attended by thousands descended into violence as police and anti-government protesters clashed in Kinshasa.
Protesters are angry at what they see as an attempt by President Joseph Kabila to extend his tenure by plotting to delay elections scheduled for this November until next year, something his supporters deny.
Suspected rebels have killed at least 30 civilians in the Democratic Republic of Congo, the army said - making it the deadliest massacre in the conflict-stricken country so far this year.
Local army spokesman Mak Hazukay said the militants were believed to belong to the Allied Democratic Forces, a Ugandan Islamist group which has operated in eastern Congo since the 90s.
They struck the village of Rwangoma, about 5km (3 miles) south of the commercial hub of Beni on Saturday night at around 7pm local time (6pm BST).
Model Poppy Delevingne has lent her support to Save the Children's No Child Born to Die campaign.
The 29-year-old visited the Democratic Republic of the Congo to meet mothers whose children were dying from preventable conditions such as malaria, pneumonia and malnutrition because of a lack of trained doctors, medicines, health facilities and equipment.
According to Save the Children, the number of children dying from preventable diseases has dropped from 12 million to 5.9m - but the charity is now calling for an international pledge to end it completely by 2030 by ensuring everybody has access to basic healthcare.
A 75-year-old missionary midwife, awarded an OBE in the New Year Honours List for her work overseas, has been shot while working in the Congo.
Maud Kells, from County Tyrone in Northern Ireland, was shot twice in the shoulder during an armed robbery at her home in Mulita.
Ms Kells spends half her time in the country working in medical centres for Christian aid organisation WEC International, and half in her home town in Cookstown.
A spokesman for WEC International said she was now in a stable condition, and said the bullets had not broken any bones nor hit any major muscles.
The robbery came just days after she was named in the Queen's New Year Honours list.
Officials in the DRC have said 129 people have drowned after a boat capsized in Lake Tanganyika in the DRC, AFP report.
Lake Tanganyika is the longest fresh water lake in the world and also borders Tanzania, as well as Burundi and Zambia.
At least 26 people have drowned after a boat capsized near the south eastern border of the Democratic Republic of Congo, AFP reports.
The vessel was travelling from Kalemie in Katanga to the conflict ravaged South Kivu province and got into trouble in the early hours of Friday.
Katanaga's transport minister Laurent Kahozi told the AFP said around 221 passengers were rescued and that the boat appeared to overloaded.
Foreign Secretary William Hague has condemned a massacre in the Democreatic Republic of Congo that has seen dozens, including pregnant women and children, brutally killed.
The victims of a massacre in the Democratic Republic of Congo included several pregnant women, had been shot, stabbed or burned inside their homes.
A Reuters cameraman on the scene counted 37 bodies, some of them lying inside a village church.
"It is Congolese who have carried out these attacks. It was about a dispute over cows," South Kivu governor Marcellin Cishambo told Reuters.
"The problem is that everyone in this area carries a weapon."
Thirty-seven people including women and children were killed in Democratic Republic of Congo's eastern region of South Kivu following an attack early on Saturday morning, according to a witness.
The victims had been shot, stabbed or burned inside their homes. Some of the bodies lay inside a village church, according to a Reuters cameraman on the scene.
South Kivu governor Marcellin Cishambo confirmed the attack, but gave a lower estimate of 27 for the number of dead.
Fans in Kinshasa grew angry on Sunday evening after their local team was defeated 1-0 by a team from the eastern town of Lubumbashi in a heated final, according to the local minister for the capital's inner city.
"Four policemen were harassed by supporters. When they fired tear gas, the stampede began, causing the deaths," Emmanuel Akweti told Reuters.
Akweti said 15 people died of suffocation and 24 were injured.