International aid efforts are gathering pace, following Saturday's earthquake in Indonesia that killed thousands.
Medical services in Java have been overwhelmed
The UK has pledged $5.5m (£3m), while Canada, China, Australia and the US said they would give about $2m each.
The EU immediately granted more than $3m and many countries pledged medical relief teams and emergency supplies.
UN Secretary General Kofi Annan expressed his sadness and said a UN disaster response team was ready to help with humanitarian relief.
Indonesian President Susilo Bambang Yudhoyono is in Yogyakarta to co-ordinate rescue operations.
The earthquake has devastated a densely populated part of Java's south coast.
Local hospitals and services have been overwhelmed by the thousands of casualties. Some 200,000 people are believed to have been displaced.
The Red Cross launched an appeal for $10m (7.7m euros), while Unicef said it was sending emergency supplies including 2,000 tents, 9,000 tarpaulins and hygiene kits.
"Unicef is mobilising resources to assist those who have been injured, those in need of shelter, and children who have lost family members," Kathryn Donovan, the agency's director said.
The World Food Programme is sending a rapid assessment team as well as humanitarian aid.
The UK's International Development Secretary, Hilary Benn, announced £3m ($5.5m) of unspent money given to the UN following the 2004 Asian tsunami would be diverted to the crisis.
Officials from the British Embassy in Jakarta were travelling to the region to assess the devastation, as were two experts sent by the Swiss foreign ministry.
The EU freed up $3m "to have immediate funding available for essential relief activities," Development Commissioner Louis Michel said.
EU governments have been put on "pre-alert" that search and rescue teams may be asked for, the AFP news agency reports.
The US pledged $2.5m but AFP news agency quoted administration officials as saying that this was just the first step in aid to Indonesia, which is still recovering from the devastation of the December 2004 tsunami.
In other offers of assistance:
- Italy says it will send 27 tonnes of aid, including tents, blankets, cooking sets, electric generators and water purification equipment
- Malaysia, which neighbours Indonesia, says a 56-member search and rescue team, five doctors and paramedics as well as medical supplies left for the region late on Saturday
- Singapore sends doctors and a search-and-rescue team
- Japan and South Korea send medical and rescue teams
- Norway and Japan said they were sending relief and medical teams, and Turkey said its emergency response team was on hand, having been stationed in Indonesia since the tsunami.
Kofi Annan was "deeply saddened" by the tragedy, his spokesman said. The EU's top diplomat Javier Solana told Indonesia: "I feel very close to your grief in these difficult moments".
The Vatican sent a telegram on behalf of the Pope, who is in Poland, expressing his condolences and encouraging everyone involved in the rescue effort "to persevere in their efforts to bring relief and support".