Rebels led by the M23 group claim to have taken control of Goma, a key city in the eastern Democratic Republic of the Congo.

By Yassin Kombi and Sonia Rolley GOMA, Democratic Republic of Congo (Reuters) - Rwandan-backed rebels strengthened their control over east Congo's largest city, Goma, on Wednesday as columns of Romanian mercenaries hired to fight for Congo entered Rwanda under tight supervision by Rwandan security forces.

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,

Their fury is focused on Rwandan President Paul Kagame, who they accuse of backing the rebels - an accusation long made by the UN. To put it bluntly, a group of UN experts maintains the Rwandan army is in "de facto control of M23 operations",

STORY: Congo's M23 rebels appear to have consolidated control over a devastated Goma.It is the second time the Rwandan-backed rebels have entered eastern Congo's largest city.But last time, in 2012, they soon withdrew and were defeated the following year.

Congolese forces were losing control of the key city of Gom a on Wednesday after rebel groups backed by Rwanda took over the airport and shared plans to set up a new administration. Soldiers fighting for Congo - many of them mercenaries from other nations - were laying down their weapons at the border with Rwanda.

Rwanda-backed fighters controlled most of the besieged DR Congo city of Goma on Wednesday as residents slowly emerged from their homes after days of deadly fighting in the key mineral