Rwanda-backed rebels who captured eastern Congo's largest city said Thursday they want to take their fight to the far-off capital, Kinshasa, while Congo’s president called for a massive military mobilization to resist the rebellion and his defense minister rejected calls for talks.

Fierce fighting rages on in the eastern Democratic Republic of Congo city of Goma, as rebels and the army exchange fire. "All we can hear [are] gunshots around the city," one Goma resident, who has been trapped in his house since the weekend, told the BBC.

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's M23 rebels are moving south towards Bukavu, the capital of South Kivu province, in what appears to be an attempt to expand their area of control in the country's east after capturing the city of Goma.

Fighting has escalated sharply in recent weeks in eastern Congo, where rebels have seized key towns and are closing in on the city of Goma, the government’s last stronghold in the North Kivu province,

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",