Sudan’s military and allied armed groups have staved off an attack by a paramilitary group and Arab militias on a major city in the western region of Darfur.

United Nations observers and human rights organizations have said they fear the worst in the event the ongoing siege by Sudan's Rapid Support Forces on El Fasher-- the last stronghold of the opposing Sudanese Armed Forces in Darfur-- culminates in an attack.

Human Rights Watch says that after the slaughter of civilians in Darfur’s El Geneina in November, El Fashir fears a similar fate.

More than a year of brutal war in Sudan between two factions of its army has killed tens of thousands and forced more than 8 million people to flee their homes. Some 5 million are now at risk of starvation there.

A major city in Sudan's western region of Darfur has been rocked by fighting involving "heavy weaponry," a senior UN official said Saturday.

The situation in Darfur, the Sudanese Armed Forces' last stronghold, has become bleak for civilians amid a siege by the Rapid Support Forces. The conflict there may end in bloodshed and draw more actors into the war.