DUBAI, May 29 (Reuters) - Heavy and sustained clashes could be heard on Monday in parts of Sudan's capital, residents said, hours before the expiry of a shaky ceasefire deal that had brought some respite from a six-week-old conflict but little humanitarian access.

Fighting continued from Sunday into Monday in the south and west of Omdurman, one of three adjoining cities that make up Sudan's greater capital. Across the River Nile in southern Khartoum residents also reported clashes late on Sunday.

Sudan's army and the paramilitary Rapid Support Forces (RSF) have been locked in a power struggle that erupted into conflict on April 15, killing hundreds and driving nearly 1.4 million people from their homes.

Both sides have said they are considering extending a deal for a week-long ceasefire brokered by Saudi Arabia and the United States that was designed to allow for the distribution of aid and is due to expire at 9.45 p.m. (19:45 GMT) local time on Monday.

Saudi Arabia and the United States, which are also remotely monitoring the ceasefire deal and have appealed for its renewal, said on Sunday that both the army and the RSF had repeatedly violated the truce and had impeded the delivery of humanitarian access and restoration of essential services.

"Since yesterday evening there has been bombardment with all types of weapons between the army and the Rapid Support. We're in a state of great fear. Where's the truce?" Hassan Othman, a 55-year-old resident of Omdurman told Reuters by phone.

Across the country, the health ministry has said more than 700 people have died as a result of the fighting, though the true figure is likely much higher.

It has separately recorded up to 510 deaths in El Geneina, one of the main cities in Darfur, a western region already scarred by conflict and displacement.