The organisations, based in France, Switzerland, Britain, Austria and Lebanon, face a suspension of their activities if their governments accede to a request by US President George Bush to freeze their assets.
Bush said that the action was in response to a resistance bombing claimed by Hamas this week that killed 20 people aboard a Jerusalem bus.
British-based INTERPAL (Palestinian Relief and Development Fund) on Saturday called US President George W Bush’s declarations "an outrageous and political decision".
"It's just a political decision designed to discredit organisations and people who are working hard to try to improve the life of Palestinians," said the organisation's president, Ibrahim Hewitt.
INTERPAL was created in 1994 and donates packs for school children, food parcels and is involved in sponsorship schemes.
In 1995 the organisation was investigated and given a clean bill of health by the regulatory body for charities in Britain, the Charities Commission, following complaints by Zionist groups.
Bush has targeted aid bodies
in response to bombing
The French-based Committee for Palestinian Charity and Aid (Comite de Bienfaisance et de Secours aux Palestiniens, or CBSP, in French) also denied having any links with Hamas, dismissing the accusation as "ridiculous".
"Everybody knows us. If we represented any danger whatsoever, the French authorities would have made us shut down," CBSP spokesman Youcef Benderbal said on Saturday.
In Austria, a spokesman for Interior Minister Rudolf Gollia said that the Palestinian Association of Austria, registered in the country since 1993, had already been the subject of an inquiry by the Austrian authorities.
It had "not been found guilty of any reprehensible act under Austrian law according to the Austrian inquiry," the agency quoted Gollia as saying.
In Geneva, the Swiss-Palestinian Association (ASP) also flatly denied any wrongdoing, the Swiss agency ATS quoted a spokesman for the organisation as saying.
"We call on all relevant parties to not answer this American pressure, which is linked to Zionist dictates."
Sanabil Association for Relief and Development
The spokesman insisted that it steered clear of party politics. ASP's activities were "transparent" and humanitarian, and its funds registered and controlled by Swiss laws, the spokesman insisted.
In Beirut, the Sanabil Association for Relief and Development said in a statement, "Despite our complete respect and appreciation for all the nationalist and Islamic factions and forces, the association has no relation to any Palestinian movement or organisation, be it Hamas or anyone else.”
"The association provides services to Palestinian refugees in Lebanon only, and it sponsors more than 1,200 orphans and helps needy families," it added.
Sanabil, based in the southern port city of Sidon, said it was founded in 1994 by "charitable people" to help Palestinian refugees in Lebanon, home to some 390,000 Palestinians registered in a dozen camps across the country.
"We call on all relevant parties to not answer this American pressure, which is linked to Zionist dictates," it said.