Gunshots and artillery fire rocked the Sudanese capital Monday, the last day of a frequently breached ceasefire, as calls for civilians to arm themselves stoked fears the six-week war will intensify.

Residents told AFP they could hear street battles in northern Khartoum, as well as artillery fire in the south of the city.

Since the truce began a week ago, frightened residents have ventured out to try and get food or water, the costs of which they say have doubled since the start of the war.

But many families continue to shelter in place, rationing water and electricity while trying desperately to avoid stray gunfire in the city of more than five million people -- nearly 700,000 of whom have fled, according to the United Nations.

In Darfur, on Sudan's western border with Chad, continued fighting "blatantly disregards ceasefire commitments", according to Toby Harward, of the United Nations refugee agency.

"Intermittent fighting between Sudanese armed forces and Rapid Support Forces in El Fasher, North Darfur over the last few days" has seen civilians killed, homes looted and tens of thousands newly displaced in the already war-ravaged region, Harward said.