GOMA, Congo (AP) — A rebel group seeking to overthrow the Congolese government focused its aim Thursday on seizing the strategic eastern town of Bukavu, which would mark the biggest gain in rebel territory in nearly a decade if it were to fall.

The fighters believed to be backed by neighboring Rwanda already have seized the provincial capital of Goma this week and later took the nearby town of Sake on Wednesday.

The violence has forced more than 100,000 people to flee, more than half of whom are children, according to the U.N. children’s agency.

While they have vowed to overthrow President Joseph Kabila’s government, they remain some 1,000 miles (1,600 kilometers) from the capital of Kinshasa in a country of dense jungle with few paved roads.

Meanwhile, hundreds of Congolese soldiers who had retreated from Goma days earlier were holed up in Minova, a lakeside city on the road to Bukavu.

"We are waiting for orders, but they haven’t come yet. We’re hungry and have spent five days sleeping in the bush under the rain," said a Congolese army major who spoke on condition of anonymity because of the sensitivity of the matter.

The rebels are believed to be backed by Rwanda, and to a smaller extent by Uganda, which are accused of equipping them with sophisticated arms, including night vision goggles and 120 mm mortars.

A report released Wednesday by the U.N. Group of Experts said both Rwanda and Uganda have "cooperated to support the creation and expansion of the political branch of M23 and have consistently advocated on behalf of the rebels."

The report’s release, just one day after the violent takeover of Goma, is sure to increase pressure on the international community to confront the two eastern African countries over their role in neighboring Congo’s conflict.

Both Rwanda and Uganda have repeatedly denied supporting the M23 movement and have faced little international criticism over the allegations.

Goma was last threatened by rebels in 2008 when fighters from the now-defunct National Congress for the Defense of the People, or CNDP, stopped just short of the city.

Their backs to the wall, the Congolese government agreed to enter into talks with the CNDP and a year later, on March 23, 2009, a peace deal was negotiated calling for the CNDP to put down their arms in return for being integrated into the national army.

The peace deal fell apart this April, when up to 700 soldiers, most of them ex-CNDP members, defected from the army, claiming that the Congolese government had failed to uphold their end of the deal. Like in 2008, they again advanced toward Goma. This time, the city fell and the disastrous consequences for the population were already on display.