UK Foreign Office staff who had been working in Goma in the Democratic Republic of Congo are to leave the city following heavy fighting in the area, the department has said.
UN troops in the country have launched an offensive, shelling positions held by rebels near Goma.
The UN was responding to shelling from M23 rebels on Goma on Thursday, a spokesman said.
The Foreign Office said it would review the situation on Sunday.
A “small number” of staff were affected, it added.
It has also updated its travel advice, advising against all travel to some parts of the country.
UK Minister for Africa, Mark Simmonds, tweeted: “Very concerned by reports of shelling in #Goma and upstart of violence. Vital that tensions are reduced quickly.”
Congolese officials said five civilians in the city died in the shelling on Friday.
An M23 spokesman told the BBC it had not attacked the city, blaming the army for provoking the fighting.
A new UN intervention brigade is deploying to the area to tackle rebels. It has a mandate to neutralise and disarm rebel fighters.
Its 3,000 soldiers are joining the regular UN peacekeeping force, Monusco, which has more than 18,000 troops on the ground with a mandate to protect civilians.
Rwanda has repeatedly denied UN allegations that it has been backing the M23 rebels.
Like Rwanda’s leadership, M23 fighters mostly come from the Tutsi community.
They deserted from the Congolese army in April 2012, forcing an estimated 800,000 people from their homes in the ensuing unrest in the mineral-rich region.
Peace talks taking place in Uganda this year to resolve their grievances have stalled.
BBC Africa News
