NEW YORK (AP) — U.S. cell phone users have contributed more than $5 million in $10 increments to the Red Cross for Haiti disaster relief, by far the largest outpouring of support via mobile devices in history.

The response to the devastating earthquake produced the highest amount of mobile donations 'that we have ever seen,' said Jenifer Snyder, executive director of mGive Foundation, the nonprofit group that is working with the Red Cross and wireless carriers to channel the donations.

To donate to the Red Cross, mobile users are texting the word 'Haiti' to the number 90999. Snyder said the money is coming in at a rate of roughly $200,000 an hour. As of Thursday afternoon, people had donated $5.1 million.

'We could be handling more,' she said. 'We are not at capacity.'

Red Cross spokesman Roger Lao called the outpouring of $10 donations by hundreds of thousands of mobile users 'nothing short of awe-inspiring.' But he said the largest donations the organization is getting is still coming in online.

So far, the Red Cross has released $10 million for earthquake relief in Haiti.

On Thursday morning's 'The Early Show' on CBS, Secretary of State Hillary Rodham Clinton asked Americans to contribute to the Red Cross via text donations. And on social networks Twitter and Facebook, users continued to urge one another to text money as well.

Other charities, such as singer Wyclef Jean's Yele, were also collecting mobile donations. To send $5, donors can text 'Yele' to the number 501501.

Verizon Wireless said Thursday morning its users have pledged more than $1 million to the Red Cross through text donations. The outpouring easily surpassed earlier records for mobile giving.

In the aftermath of Hurricane Katrina in 2005, the Red Cross collected $400,000 from mobile users. A year earlier, following the Asian tsunami that left 230,000 people dead, the organization received $200,000 through text messages, Verizon Wireless said, citing industrywide figures.

Jeffrey Nelson, a spokesman for Verizon Wireless, called mobile donations a 'new stream of philanthropy.'

'So many folks who are texting $10 now might not have been at a place to write a check, or call a toll-free number or send mail,' he said.

Most wireless carriers said they were not charging regular text-messaging fees on top of the donations. Sprint Nextel Corp. spokeswoman Crystal Davis said the company was in discussion over how to handle regular texting fees for the donations.

T-Mobile USA Inc. said Thursday it is enabling international calls to Haiti free of charge through Jan. 31 and will retroactively credit accounts for such calls made since Tuesday. And T-Mobile users in Haiti will be able to make roaming calls on local networks Voila and Digicel thorough the end of the month, the company said.