In a historic joint statement, 12 UN agencies, the International Organisation for Migration and the World Bank - the Global Migration Group, has called for the protection of human rights of irregular migrants worldwide.
------------------
------------------
This statement is important as the issue of violation of human rights of illegal migrants becomes more and more significant and the recognition of such violations is crucial in order to promote their protection. 
Illegal immigration to other countries may be caused by several factors as in the case of wars. People migrate to other countries in fear of these wars. Other factors might include persecution whereby people illegally immigrate to the other countries in fear of being persecuted in their own country and a good example is in the case with the religious leaders. Another factor which might lead to illegal immigration is the case with poverty. Most people usually migrate to the other countries in search for higher wages. A good example is in the case with people from the developing countries. In particular, most of these immigrants usually move to the developed countries say the United States in search of well paid jobs, and improved standards of living which could not be achieved in their home country.
However, the fact that these migrants are illegal does not mean that they don't have rights that should be respected and protected. In most cases, such as Greece, illegal migrants are being kept under humiliating conditions and in the majority of the cases their right to ask for an asylum has been put on hold for months or even years, despite the fact that international law protects their rights.