The US Federal Bureau of Investigation (FBI) warned potential donors of earthquake relief funds to Haiti on Thursday to be on the lookout for fraud schemes.
"The FBI on Thursday reminds Internet users who receive appeals to donate money in the aftermath of Tuesday's earthquake in Haiti to apply a critical eye and do their due diligence before responding to those requests," the FBI said.
"Past tragedies and natural disasters have prompted individuals with criminal intent to solicit contributions purportedly for a charitable organisation and/or a good cause," the FBI said in a statement.
Email users should not respond to or click on links in unsolicited messages and should make an effort to confirm the legitimacy of nonprofit organisations raising funds for Haiti, the FBI said.
Potential donors should be cautious of emails that claim to show pictures of the disaster areas in attached files because the files may contain viruses, the FBI said.
"Do not give your personal or financial information to anyone who solicits contributions," it added. "Providing such information may compromise your identity and make you vulnerable to identity theft."
Microblogging service Twitter was deluged with messages on Wednesday on ways to "Help Haiti," which was one of the top 10 most popular topics on the site.
They included sending money by text message to the American Red Cross and to Yele.