Rwanda-backed rebels claimed they captured eastern Congo’s largest city, Goma, early Monday, as the United Nations described a “mass panic” among its 2 million people and Congo’s government said the rebel advance was a “declaration of war.

Tens of thousands of people in the Democratic Republic of Congo are fleeing towns in the east of the country as rebel forces close in on the city of Goma. Explosions and gunshots were heard in city - home to more than a million people - late on Sunday evening, according to local media reports.

The Rwanda-backed rebel group M23 is battling Congolese government forces in Congo's key city of Goma, causing the international airport there to be evacuated.