United Nations, May 1 : In light of the rapidly deteriorating humanitarian crisis in Sudan due to the violence that erupted on April 15, UN Secretary-General Antonio Guterres is sending the world body's Emergency Relief Coordinator Martin Griffiths to the country "immediately". The scale and speed of what is unfolding is unprecedented in Sudan, Xinhua news agency quoted Stephane Dujarric, spokesman for Guterres, as saying in a statement. He added that the US is "extremely concerned" by the immediate as well as long-term impact on all people in Sudan and the broader region. "We once again urge all parties to the conflict to protect civilians and civilian infrastructure, allow safe passage for civilians fleeing areas of hostilities, respect humanitarian workers and assets, facilitate relief operations, and respect medical personnel, transport and facilities," said Dujarric. More than 500 people have been killed and over 4,000 others wounded since the violent clashes broke out between the Sudanese Armed Forces and the paramilitary Rapid Support Forces, according to the country's Health Ministry. In a statement issued ahead of his trip to the region, Griffiths said that two weeks since clashes erupted, the humanitarian situation is "reaching breaking point." Goods essential for people's survival are becoming scarce in the hardest-hit urban centres, especially Khartoum, and families are struggling to access water, food, fuel and other critical commodities, he said. He warned that access to urgent health care, including for those injured in the violence, is severely constrained, raising the risk of preventable death. Griffiths said he is heading to the region to explore how to bring immediate relief to the millions of people "whose lives have turned upside down overnight". "However, the obvious solution to this crisis is to stop the fighting," said the UN relief chief. In the latest development, the two warring factions have announced their commitments to a new 72-hour humanitarian truce, effective as of midnight Sunday. "Based on the endeavours and request of the Saudi-American mediation, the Armed Forces agreed to extend the truce for extra 72 hours, to begin at the end of the current one," the Army saidin a statement. For its part, the RSF said that it agreed to the truce extension to open humanitarian passages, facilitate the movement of the citizens and enable them to get their needs and reach safe areas. On Sunday, Sudan's Civil Aviation Authority said the closure of the country's airspace will be extended to May 13. /IANS