Fighting between government troops and rebels has displaced hundreds of thousands people in the Democratic Republic of Congo (DRC), leading to what is being described as a humanitarian crisis.
Rebel fighters known as the March 23 Movement, or M23, have advanced against government forces in renewed fighting on Saturday.
The fighting has been most intense in the hills of the North Kivu province in the country's east, where rebel positions were shelled by the government forces on Friday.
Al Jazeera’s Nazanine Moshiri, reporting from the outskirts of Goma in eastern Congo, said: “We spoke to the M23 spokesperson. He said they are fighting back against government forces and have taken a place called Jomba. They believe they are going to be able to take back Bunagana. Clearly, this is unconfirmed,” she said.
“It does seem the fighting has escalated in the last few hours and it’s really serious and intense. If M23 is right in what they are saying, then this is real threat for FARDC - the government army."
The fighting has created a refugee crisis with influx of people into neighbouring Rwanda and Uganda fearing violence, and many more are on their way.
The United Nations High Commissioner for Refugees [UNHCR] says about 300,000 people have been displaced because of the fighting since November's presidential and parliamentary elections.
More than 8,000 refugees have crossed into Rwanda in the past three weeks on top of 55,000 Congolese refugees already there.
"The initial challenge is shelter because the camp is over-stretched and over-congested," Anouck Bronee of UNHCR said.
Another 30,000 have gone to Uganda this month, in addition to the 175,000 other refugees from several of its neighbours.
In a statement issued earlier this week, Antonio Guterres, the UN high commissioner for refugees, said: "The displacement level we see in eastern Democratic Republic of the Congo is already disastrous.
"Conflict there, coupled with very limited access for humanitarian workers, means that many thousands of people are without protection and help. And now people in need are appearing in neighbouring countries too."
The UN fears the fighting could escalate and draw in various rebel groups in the region.
Fatoumata Lejeune-Kaba, UNHCR spokeswoman, told Al Jazeera: "These numbers are really staggering when you consider the short period of time during which we have all these movements."
"Of course, this is not new for Congo. The eastern part of Congo has been experiencing conflict on and off for close to 15 years," she said.
"What is making extremely difficult for civilians is that each time they feel that they are finally at peace and go back home, they face a new crisis that forces them to move across to other villages or other parts of DRC or even to Rwanda and Uganda."
The military has been fighting the rebels since late April in Masisi territory, northwest of the provincial capital of Goma.
M23 comprises of ex-members of the rebel National Congress for the Defence of the People (CNDP) who were integrated into the national army under a 2009 peace deal, but later defected, complaining of poor conditions.
Former CNDP commander Bosco Ntaganda is accused of leading the mutiny.
Ntaganda is wanted by the International Criminal Court on a war crimes charge of enlisting child soldiers.
On Wednesday, Human Rights Watch said he was again forcing boys into military service, accusing him of forcibly recruiting at least 149 boys aged between 12 and 20 in the latest conflict.