M23 rebels in eastern Democratic Republic of Congo have declared a ceasefire for UN chief Ban Ki-moon’s visit to the conflict-hit area, a spokesman for the group says.

Mr Ban has arrived in the regional capital Goma, where one person was killed in a rocket attack on Wednesday.

He was deeply concerned by the renewed fighting, Mr Ban said.

Earlier, the World Bank unveiled a $1bn (£660m) aid package to help DR Congo and its neighbours.

World Bank head Jim Yong Kim, who is also visiting DR Congo, said the money would be used for health, education, cross-border trade and hydroelectricity projects.

At least 20 people have been killed since Monday in heavy fighting between government and M23 forces.

These have been the first clashes between the two sides since the rebels pulled out of Goma last year, after seizing the city in November.

‘Crucial timing’

UN peacekeeping officer Col Premanku Ghosh said two rockets had exploded in Goma’s Ndosho neighbourhood on Wednesday and that civilians were among the casualties.

“We’ve decided to announce this ceasefire to allow His Excellency Ban Ki-moon to visit Goma as he promised,” M23 political spokesman Amani Kabasha told Reuters news agency.

“We also want to give peace a chance and ask the government to come back to the negotiating table in Kampala,” the Associated Press news agency quoted him as saying.

Joanna Trevor, from the UK charity Oxfam, said Mr Ban’s visit was a “welcome injection of high-level diplomacy, much needed at this time”.

“Thousands of people are again homeless after a new explosion in violence forced them to flee the camps where they had sought protection and refuge,” she said in a statement from DR Congo.

“People don’t know where to go to find safety. For all the talk and signed pieces of paper over the past few months, civilians on the ground… are still at daily risk of attack.”

Speaking earlier in the capital, Kinshasa, Mr Ban said the world community would stand with DR Congo.

“We are in a very crucial and important timing. The Security Council recently strengthened the mandate and role of the United Nations peacekeeping mission (Munusco) with the introduction of an intervention brigade,” he said.

The UN has nearly 20,000 peacekeepers in eastern DR Congo. The 3,000-strong brigade will have the mandate to neutralise and disarm the rebels.

“This is again an unprecedented one and I am sure that this will bring peace and security at this time,” Mr Ban said.

The BBC’s Gabriel Gatehouse in Goma says that by some estimates there could be as many as 50,000 armed men in the region, belonging to several dozen armed groups.

An estimated 800,000 people have fled their homes since the M23 launched its rebellion last May.

Announcing the aid package, Jim Yong Kim said the new funding could be “a major contributor to a lasting peace”.

The package is to support a peace deal signed in February between DR Congo and its neighbours, some of whom are accused of backing the rebels.

The largest tranche of the aid – $340m – will go towards an 80-megawatt hydroelectric project in Rusumo Falls, providing electricity to Burundi, Rwanda and Tanzania.

Despite its vast mineral wealth, decades of conflict and mismanagement mean most Congolese remain stuck in poverty.

Mr Ban and Mr Kim are also due to visit Rwanda and Uganda.

Last year, a UN report accused the two countries of backing the M23, an allegation they denied.