(CBS) – People who want to donate relief aid in the wake of the devastating earthquake in Nepal should be careful not to be taken by scams, a consumer advocacy agency warns.

The 7.8-magnitude earthquake over the weekend has killed thousands and set off an avalanche that killed at least 18 at the base of Mt. Everest.

Fraudulent charities and individuals often spring up following  natural disasters.

“Unfortunately, we’ve seen time and time again that scammers will try to take advantage of the generosity of the public after a disaster,” Steve J. Bernas, president and CEO of the Better Business Bureau, says in a news release.

He says it’s important to research before donating. Charity groups reluctant to answer questions about their operations should be avoided.

There are several reputable humanitarian organizations with proven track records in helping distribute funds or aid, Bernas says.

For more information, go to www.bbb.org/charity.

Don’t give your credit card number or other personal information to a telephone solicitor or in response to an e-mail solicitation, the bureau advises.