British Prime Minister Rishi Sunak said on Sunday the country’s armed forces evacuated diplomatic staff and their family members from Sudan.

Sunak paid tribute to what he called a “complex and rapid” evacuation after he said there had been a significant escalation in violence and threats to embassy staff. But British nationals living in Sudan were not rescued.

“I pay tribute to the commitment of our diplomats and bravery of the military personnel who carried out this difficult operation,” Sunak said on Twitter.

“We are continuing to pursue every avenue to end the bloodshed in Sudan and ensure the safety of British nationals remaining in the country.”

Britain’s defence minister, Ben Wallace, said British troops undertook the rescue operation alongside the United States, France, and other unnamed allies.

The eruption of fighting in Sudan eight days ago between the army and Rapid Support Forces paramilitary group has killed hundreds of civilians and trapped many thousands in their homes.

Wallace said more than 1,200 military personnel were involved in organising and carrying out the rescue operation.

The foreign minister James Cleverly said a top priority remained the safety of British nationals. He advised British citizens in the country to shelter indoors and to tell the foreign ministry where they are staying.

A British citizen named as William told Sky News he had not heard anything from the foreign ministry and wanted to know that a plane had been prepared to take them out.

He said it was not feasible for British citizens to get past the checkpoints in the country and drive hundreds of miles to reach the Sudan border.