The president of crisis-hit Democratic Republic of Congo was set to meet his Rwandan counterpart at an emergency summit on Wednesday, as fighters backed by Kigali appeared on the brink of seizing the key city of Goma.

The M23 armed group took control of Goma’s airport on Tuesday, a security source said, following days of intense clashes that killed more than 100 people and wounded nearly 1,000, according to an AFP tally of tolls from the city’s overflowing hospitals.

It remained unclear how much of the provincial capital was under the control of Congolese forces versus the Rwandan-backed M23, which claimed it had taken the city on Sunday.

But as fighting eased on Tuesday night, only M23 fighters and Rwandan forces were visible on the streets, according to AFP journalists.

The security source said “more than 1,200 Congolese soldiers have surrendered and are confined” to the airport base of the UN’s mission in the DRC.

Congolese leader Felix Tshisekedi was to meet Wednesday with Rwandan President Paul Kagame at an “extraordinary” summit of the East African Community hosted by Kenya, its president said.

The M23’s lightning offensive marks a major escalation in the DRC’s troubled east, haunted by the legacy of the 1994 Rwanda genocide and plagued by fighting between armed groups backed by regional rivals in its aftermath.

It has also triggered a spiralling humanitarian crisis, with the UN warning of hundreds of thousands forced from their homes, serious food shortages, looted aid, overwhelmed hospitals and the potential spread of disease.

Destin Jamaica Kela, who fled across the border to Rwanda as fighting raged in Goma, told AFP that “things changed very fast”.

Bombs were falling and killing other people everywhere, we saw dead bodies,” the 24-year-old said.

On the other side of the country, roughly the size of western Europe, protesters in the capital Kinshasa attacked the embassies of various nations – angered that they had not stepped in to halt the chaos in the east.

The missions of France, Belgium, the United States, Kenya, Uganda and South Africa were among those targeted, with demonstrators torching tyres outside several.

Protesters also attacked the Rwandan embassy in Kinshasa.

The US embassy told its citizens to leave the country following the attacks while the European Union’s foreign policy chief Kaja Kallas branded them as “unacceptable” and “deeply troubling”.

The International Committee of the Red Cross said it was striving to help respond to a massive influx of wounded to Goma’s “overwhelmed” hospitals, warning that some patients were “lying on the floor due to lack of space”.

At a UN Security Council meeting on the crisis on Tuesday, the world body’s peacekeeping force in the DRC warned that the fighting risked reigniting ethnic conflicts dating to the Rwandan genocide and beyond.

In the past four days, the Human Rights Office has documented at least one case of ethnically motivated lynching in a (displaced persons) site in Goma,” Vivian van de Perre of the UN’s DRC mission MONUSCO said.

After a previous meeting of the council on Sunday, the Congolese government expressed “dismay” at its “vague” statement, which stopped short of naming Rwanda.

At an emergency meeting on Tuesday, the African Union called on the M23 to “lay down arms”, also without naming Rwanda.

The DRC has accused Rwanda of wanting to profit from the region’s abundant minerals – which include gold, coltan, copper and cobalt – and has called for stronger UN action.

Rwanda has denied the claims, saying its aim is to tackle an armed group called the FDLR, created by former Hutu leaders of the 1994 genocide in Rwanda who massacred Tutsis.

In a call with Kagame Tuesday, US Secretary of State Marco Rubio “urged an immediate ceasefire in the region, and for all parties to respect sovereign territorial integrity”.

Also on Tuesday, China’s ambassador to the UN, Fu Cong, urged Rwanda to heed international calls to “stop military support” for the M23.

At least 17 peacekeepers from a southern African regional force and the UN’s DRC mission have been killed in the fighting.