Rwanda-backed rebels claimed they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped, the Associated Press reported.

The Government of the Democratic Republic of Congo (DRC) said Monday that the “Rwandan Army” is in the strategic Congolese city of Goma (northeast), taken by the rebel group Mar. 23 Movement (M23), allegedly supported by neighboring Rwanda.

Congolese forces were losing control of the city of Goma on Wednesday after rebel groups backed by Rwanda took over the airport and shared plans to set up a new administration.

Democratic Republic of Congo President Felix Tshisekedi has vowed “a vigorous and coordinated response” against a rebel alliance that has besieged swaths of the nation’s mineral-rich east and forced hundreds of local troops and foreign mercenaries to surrender.

The United Nations expressed deep concern at reports of M23 rebels and Rwandan troops advancing south towards the Congolese city of Bukavu on Thursday, as the militants sought also to assert their control over east Congo's largest city Goma.

M23 rebels in the Democratic Republic of Congo were reported to have taken the key eastern city of Goma in fierce fighting with government forces that sent streams of refugees fleeing area communities.

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,

M23 rebels, with support from Rwandan troops, marched into Goma earlier this week and are now advancing south toward Bukavu.

By Yassin Kombi and David Lewis GOMA, Democratic Republic of Congo (Reuters) - Rwandan-backed M23 rebels in Democratic Republic of Congo were moving south on Wednesday towards Bukavu, the capital of South Kivu province,

Nearly 300 foreign mercenaries hired by the Democratic Republic of Congo government to counter a swift offensive by Rwandan-backed M23 rebels in the east have surrendered and were on their way home on Wednesday.

GOMA, Democratic Republic of Congo (Reuters) - Rwandan President Paul Kagame blasted criticism of his country's role in eastern Democratic Republic of Congo where rebels his government backs have seized its largest city, saying Kigali is prepared for "confrontation" if necessary.