Aid is already arriving in areas affected by Sunday's earthquake
Global aid organisations have launched urgent appeals for donations to help survivors of the Indian Ocean earthquake disaster.
More than 220,000 people are confirmed killed by the waves and millions more are homeless.
Many governments and organisations - including the US, Canada, Australia, the EU and the UN - are sending aid.
The UN has warned that supplies are urgently needed to support the survivors and to try and prevent disease which, it says, could double the death toll.
The Disasters Emergency Committee - www.dec.org.uk - is an umbrella group of UK aid organisations - including Action Aid, British Red Cross and Oxfam - working to provide clean water, food and shelter to thousands. To call from the UK, dial 0870 60 60 900.
The United Nations World Food Programme - www.wfp.org - is seeking donations to feed victims of the earthquake.
The United Nations Children's Fund, Unicef - www.unicef.org.uk - is working to meet the "urgent needs of hundreds of thousands of people" affected by the tsunami disaster.
The UN refugee agency, UNHCR - www.unhcr.ch -
which has been helping victims of conflicts in Indonesia and Sri Lanka, is delivering relief supplies to tsunami survivors in both countries.
Save the Children - www.savethechildren.org.uk - has more than 400 people working in Sri Lanka, India, Indonesia and the Maldives.
The World Health Organization - www.who.int - is helping local health authorities establish early warning systems for disease outbreaks.
Anti-poverty organisation Care International - www.care.org - has already provided food for thousands of affected people in Sri Lanka.
Cafod, the Catholic
Agency for Overseas Development - www.cafod.org.uk - is working with partners across Asia to provide shelter, food aid and medical assistance, and assessing what further relief is needed.
The Red Cross, with its sister charity the Red Crescent, is supplying blankets, cooking utensils and other crucial goods. It has had to set up a new site - www.ifrc.org - because of the unprecedented demand from people wanting to make donations.
The Hindu Forum Disaster Relief Task Force - www.hinduforum.org - comprises 50 organisations and is raising money, clothes and medicines. Donations can be made online or by calling the ISKCON Disaster Appeal on 01923 856848 or Sewa International on 0116 261 0303.
Christian Aid - www.christianaid.org.uk - has already allocated £250,000 from its emergency fund to help the victims of this disaster but says more money is needed.
Christian charity Tearfund - www.tearfund.org - and its partners in Sri Lanka and India are helping devastated fishing communities and coastal villages get back on their feet.
Islamic Relief - www.islamic-relief.com - has also launched an appeal to provide medical supplies, tents and sanitation facilities for those affected.
The YMCA's international relief and development agency www.ycare.org.uk has raised more than £2m. The money is being sent to YMCAs in India and Sri Lanka which are organising distribution of food, clothing and medicine.
The Islamic Aid Emergency Relief Fund - www.islamicaid.org.uk - aims to provide immediate relief and long-term support to people in the affected areas.
Another Islamic charity, Muslim Hands - www.muslimhands.org - is collecting money and sending volunteers to help in Indonesia and Malaysia.
Medair - www.medair.org - is providing emergency support to agencies with a long-term presence in Sri Lanka and its medical experts are assessing the likelihood of malaria and diarrhoea.
Handicap International - www.handicap-international.org.uk- is focusing its efforts on helping displaced people, disabled people and vulnerable groups such as pregnant women, elderly people and children. It is trying to raise £425,000.
World Vision - www.worldvision.org.uk - has also launched an appeal and has already delivered relief goods to thousands.
The International Medical Corps www.imcworldwide.org.uk
is a humanitarian organisation providing healthcare, nutrition and training. In Aceh, Indonesia, it is helping to deliver medical assistance, nutrition, sanitation and counselling.
Concern - www.concern.net - is working with local partners to meet the needs of families in the devastated coastal villages of Tamil Nadu, the worst-affected state in India.
The International Rescue Committee - www.theirc.org - is providing emergency supplies and materials to "people most affected by the crisis".
The Salvation Army - www.salvationarmy.org.uk has local teams working in a number of affected areas and has sent a team from its international headquarters.
Muslim Aid - www.muslimaid.org - has already allocated £1m towards emergency relief in Indonesia, Thailand, Sri Lanka and India.
Action Aid - www.actionaid.org - is the biggest charity working in south India. It is focusing its relief work on the coast of Tamil Nadu, where 7,000 people died. It is working on providing medical assistance and sanitation for the survivors.
Oxfam - www.oxfam.org.uk - is active in Indonesia, the Andaman and Nicobar Islands, Sri Lanka and India. Their relief operations include distributing food packs and hygiene kits and setting up water and sanitation facilities.
Asia Quake Relief Appeal UK, a UK-based Sri Lankan organisation, is also raising money and can be e-mailed at firstname.lastname@example.org.
World Jewish Aid - www.worldjewishaid.org.uk - is working with local partners in India, Indonesia and other affected areas to help survivors threatened by water contamination and disease.
Hindu NGO Baps Care International - www.bapscare.org - is working in villages around Chennai in Southern India distributing food, drinking water, tarpaulins, utensils, stoves, clothes and blankets.
Goal teams - www.goal.ie - are at present working in Tamil Nadu in Southern India where they are distributing aid to 5,000 families.
A large team of doctors, engineers and logisticians are also in Sri Lanka.
Action Against Hunger - www.aahuk.org - has projects in about 40 countries, including Indonesia and Sri Lanka.
Merlin - www.merlin.org - a medical relief agency, is working with victims of the disaster in Sri Lanka and Indonesia.
The US Committee for Refugees - www.refugees.org - is raising money to assist Burmese refugees in southern Thailand in need of health care, sanitation, and other basic disaster relief assistance.
You can donate to all the campaigns via their websites.