Leaders from east and southern Africa have called for an immediate and unconditional ceasefire to end the deadly fighting in the Democratic Republic of Congo.

At a crisis summit in Tanzania, the Southern African Development Community and East African Community (EAC) blocs urged all warring parties to hold peace talks within five days, including with the Rwanda-backed M23 rebels.

The rebels – fighting government forces – have seized vast swathes of land in the eastern DR Congo, including the city of Goma. Their push towards Bukavu has raised fears of a wider regional war.

As part of their talks, army chiefs have also been told to draw up a security plan for Goma and surrounding areas.

A recent UN warning estimated the hostilities between M23 and the armed forces of the DR Congo had displaced at least 700,000 people, killed at least 900 and injured over 2,000 since early January.

Last week alone, the UN said at least 700 people had been killed and another 2,800 injured in a matter of days.

The gathering in the commercial city of Dar es Salaam brought together heads of state and government representatives to try to resolve the worsening security and humanitarian situation.

“The summit emphasises that political and diplomatic engagement is the most sustainable solution to the conflict,” said the follow-up communique.

It also demanded the reopening of Goma airport and other key routes to facilitate humanitarian aid, as well as the withdrawal of uninvited foreign armed forces from Congolese territory.

M23, which is made up of ethnic Tutsis, say they are fighting for minority rights while DR Congo’s government says the Rwanda-backed rebels are seeking control of the eastern region’s vast mineral wealth.

Rwandan President Paul Kagame – who was at the summit – has repeatedly denied any involvement in supporting the rebels.

But, as reported last month by the BBC’s Ian Wafula, a group of UN experts maintains the Rwandan army is in “de facto control of M23 operations” – detailing how M23 recruits are trained under Rwandan supervision and supported by high-tech Rwandan weaponry.

Following the summit, Kagame posted on Facebook, accusing the DR Congo of “mounting a security problem against our country”.

The DR Congo’s President, Félix Tshisekedi, opted to appear at the summit via video link. Prime Minister Judith Suminwa was there in person.

There was no immediate response from Suminwa or the Congolese delegation to the joint communique.

Kenyan President William Ruto, the current EAC chairperson, stressed military solutions alone could not resolve the crisis.

“We must resist the temptation to think that we can somehow shoot or bombard our way into a solution in the face of such a complex situation,” he said.

Tanzanian President Samia Suluhu Hassan underscored a “collective responsibility” of regional leaders to end the conflict, saying “history will judge us harshly if we remain still and watch the situation worsen day by day”.

The ongoing conflict dates back to the 1990s, but has rapidly escalated in recent weeks.

The DR Congo is so vast – two-thirds the size of Western Europe – that it is a member of both the East and Southern African blocs.