Rebel group M23 says it is ready to march on the capital city of Kinshasa and take control of the Democratic Republic of the Congo Reuters

The rebel group M23 has said it is ready to march on the capital city of Kinshasa and take control of the Democratic Republic of the Congo (DRC), having captured Goma, the main city in the east of the country.

At a gathering of civilians, police and government soldiers at the Stade du Volcan football stadium in Goma, thousands of Congolese troops defected to the rebels, as the M23 military spokesman Lieutenant Colonel Vianney Kazarama issued a message to the president, Joseph Kabila.

"People say we have balkanised the Congo, but that is wrong. We will go to Kinshasa, we will unite the country," he announced. "The DRC is indivisible. Nobody will divide the country." The crowd cheered its approval. Later, Kazarama told journalists: "We will go to Kinshasa if the people there invite us. We obey the will of the people. If they want Kabila [to resign], we will support the people."

M23 seized control of Goma early on Tuesday afternoon after a brief fight with government troops in the centre of the city. The Congolese army soldiers – poorly supplied, underfed and rarely paid – fled the city without putting up any resistance of note. On Wednesday, the rebels began the process of recruiting army deserters and government police and securing a city that was left lawless as government agents fled alongside troops.

In an effort to prevent an escalation of the rebellion in the central African country, Kabila flew to Kampala, Uganda, to meet Paul Kagame, the president of Rwanda, and Yoweri Museveni, president of Uganda. Rwanda and Uganda are accused of supporting the rebels.

Kabila's troubled government remains unwilling to negotiate with the M23. "We're no longer going to respond to these people who work for someone else," government spokesman Lambert Mende told Reuters, referring to the allegations of Rwandan and Ugandan support for M23. "We're negotiating with those who they work for … Even if Rwanda takes Kinshasa, we'll continue to fight."

At the football stadium, Lieutenant Colonel Eric Mankesi Ndamba was one of the highest-ranking government troops who had come to join M23. "The soldiers are hiding, afraid to come out," he said. "But I will address them, and they will join M23 as I am doing." By the end of the morning he said he had compiled a list of 2,100 soldiers who would defect to the rebels, alongside 700 police.

Kazarama also confirmed M23 troops were moving along the road west out of Goma, following the route taken by the deserting army soldiers. He said the rebels had taken control of Sake, a town some 20 miles (30km) away, and that their intention was to head to Bukavu, the capital of South Kivu province. The capture of Sake was confirmed by a UN source.

"The priority is to restore the security of the population of Goma," said M23's political leader, Bishop Jean-Marie Runiga. "The people who worked in the provincial government administration will continue to do their work, though eventually we will make political appointments. It is not yet time for that, though."

Kazarama strenuously denied claims that the rebels were linked to Rwanda, insisting M23 was a Congolese affair. He offered a pardon to government soldiers and police and urged them to return to Goma and join the rebels who were working, he said, in the interests of the people.

Human Rights Watch, however, said M23 had committed "widespread war crimes in eastern [DRC]" and that "the United States government should publicly support sanctions against Rwandan officials backing the armed group". There are reports that local human rights defenders have fled Goma, fearing for their security under M23 rule.

There is no credible challenge to M23 control in Goma, and the rebels have taken towns to the west of the city unopposed as they march towards Bukavu. The government troops are disorganised and demoralised; for now there seems to no way for Kabila's administration to prevent the rebels' advance.