Large numbers of Rwandan troops have been flowing across the border into the Democratic Republic of the Congo to assist militants in seizing the regional capital of Goma ahead of an emergency UN summit on the issue on Monday, intelligence officials warned.

In early January, rebel forces from the M23 movement, supported by Rwanda, seized control of a key town in the eastern DRC.

Rwanda Defense Force (RDF) personnel are thought to have quietly infiltrated into eastern DRC in recent days to support the M23's onslaught.

Officials speaking to The Observer on condition of anonymity stated that the RDF had increased pressure on the beleaguered Congolese city by assembling large numbers of troops on the Rwandan side of the border, just a few hundred meters from central Goma.

The majority of the RDF's top commanders are also claimed to be stationed in Gisenyi, Rwanda, which is less than a mile from Goma, and someone with insider knowledge told The Observer that the Rwandan army is "lined up at the border, ready to invade."

On the outskirts of Goma, fierce battles between M23 advance groups and the Congolese army were reported all day on Saturday, leading to the death of 9 South African troops and a Uruguayan member of the UN peacekeeping mission, in addition to the injury of four others.

The battle seemed to be pushing even closer to Goma's outskirts, with one source claiming that combat had reached Nzulo, almost within the city boundaries, bypassing the massive refugee camps that house more than a million people displaced by the conflict.

According to Congolese army sources, the Rwandan-backed M23's onslaught was halted overnight. An anonymous intelligence source expressed that “Goma’s defenses are just about holding out, but they [Rwanda] want to take Goma before the UNSC."

The United Nations Security Council, which is in charge of maintaining international peace and security, is slated to conduct an emergency meeting on Monday to examine the ongoing situation.

Intelligence sources suggest Rwanda plans to seize Goma before Western intervention, requiring M23 forces to break through defenses and capture the city, where up to 4,000 Rwandan troops are already operating.

M23 militants have seized key towns near Goma, including Minova and Sake, disrupting the supply of food and goods, with reports suggesting Rwanda may target Bukavu next.

Clémentine de Montjoye of Human Rights Watch told The Observer on Saturday that the situation in Goma is "extremely dire" with reports of continued combat on the two axes north and west of the city, as well as water and electricity shortages.

"Given the huge number of civilians currently seeking shelter in Goma, it is vital that pressure be mounted on all parties to protect civilians and civilian infrastructure such as hospitals, and allow access to vital humanitarian aid."

Many commentators are skeptical of the West's approach to the brewing crisis, notably its reluctance to rein in Rwanda's president and RDF leader, Paul Kagame. Critics accuse the UK, US, and France, three of the five permanent members of the UN Security Council, of being too close to Kagame.

In a statement issued on Saturday, the EU said, "Rwanda must cease its support for the M23 and withdraw."