Congolese security forces on Tuesday tried to slow the advance of Rwanda-backed M23 rebels, U.N. officials reported violence, looting, and bodies in the streets.

 Congolese security forces on Tuesday tried to slow the advance of Rwanda-backed M23 rebels who say they have captured Goma after entering eastern Congo’s largest city, as U.N. officials reported violence, looting, and bodies in the streets.

The officials said hospitals are overwhelmed in Goma, a regional trade and humanitarian hub that is a refuge for hundreds of thousands now fleeing gunfire and shelling in the major escalation in one of Africa’s longest conflicts. The violence echoed far from Goma as protestors in the country’s capital attacked at least 10 embassies, including those of France and the U.S., which urged citizens to leave the city.

The M23 rebels are one of about 100 armed groups vying for a foothold in the conflict-battered North Kivu province — which includes Goma — rich in minerals critical to much of the world’s technology.