GENEVA, June 19 (Reuters) - International donors made pledges on Monday of close to $1.5 billion in aid for Sudan and the surrounding region, about half of estimated needs for a deepening humanitarian crisis that has driven some 2.2 million people from their homes.

The conflict between Sudan's army and paramilitary Rapid Support Forces (RSF) has turned the capital Khartoum into a war zone and triggered lethal, repeated attacks and mass displacement in the western region of Darfur as well as other parts of the country.

Though a 72-hour ceasefire has brought a lull in fighting in Khartoum since Sunday, residents reported that looting had surged as clashes subsided and the International Committee of the Red Cross (ICRC) said gunfire had prevented the transfer of wounded soldiers to hospital.

In El Geneina, the worst hit city in Darfur, desperate residents have been trying to flee attacks by Arab militias, but face murder, rape or detention as they set out on foot for the nearby border with Chad, witnesses and aid workers say.

A fundraising conference in Geneva hosted by Germany, Saudi Arabia, Qatar, Egypt and the United Nations was meant to drum up pledges to support relief efforts that have been hampered by ceasefire violations, looting and bureaucratic controls.

Donors announced close to $1.5 billion in pledges, U.N. aid chief Martin Griffiths said, though it was not immediately clear if all the money was new or when it would be disbursed.

That included 200 million euros ($218 million) from Germany and $171 million from the United States. The European Union said it had committed 190 million euros, and Qatar pledged $50 million.

"This crisis will require sustained financial support and I hope that we can all keep Sudan at the top of our priorities," Griffiths said.

USAID chief Samantha Power said the U.S. had contributed more than half the funding for Sudan, which she described as unsustainable.

"The funds pledged today fail to meet the urgency of the situation," said David Macdonald, of humanitarian agency CARE.